Spud is a deaf double-merle French Bulldog. In our one and only testing session with him, he never developed a positive conditioned emotional response (CER) with the vibration and treats. Further, with more trials, he began to grow anxious, so we ended the testing.
I found the concept of a vibration collar potentially useful. But in practice, there were a number of things I didn’t like about the Wolfwill vibration collar:
It’s marketed as an aversive. The text on the box says, “When you push on a button… He’ll quickly learn the association between his behavior and your correction; in no time, you’ll have a better-behaved pet.” The instruction booklet inside also describe its use as a punishment tool rather than as a positive communication tool.
There is no instruction offered about conditioning your dog to be comfortable with the collar before you use it and nothing about it being very inappropriate to use with a dog who is “hiding or acting fearful.”
The instruction guide is almost incomprehensible. As this product is made in China, the instructions were full of translation errors – annoying, but not insurmountable. Still, it made already difficult-to-follow instructions even more difficult. Due to the poor instructions, initially I couldn’t get the two units (transmitter and receiving collar) to charge. When I contacted the company for help, they wanted to see my receipt before they would help me! I finally figured out what I was doing wrong on my own.
The collar is supposed to be suitable for dogs 22 to 88 pounds. I wouldn’t even consider putting it on Sunny, my 25-pound Pomeranian-mix, as the receiver box is quite large and the collar is way too bulky for a small dog.
On two occasions, as I was trying to change intensity of the vibration, it kept sticking. I pressed the appropriate button repeatedly, and sometimes it would change. Sometimes it wouldn’t.
The product touts its three-function features – vibration, light, and tone (sound) – but in our opinion, only the vibration is useful. The vibration does, indeed, work well. The tone is obviously useless for a hearing-impaired dog and isn’t really loud enough for the human to locate a lost deaf dog unless the dog is very close. We’re not sure why you would need a tone for a hearing-abled dog when you can use your voice or a whistle. The light also seems worthless. It can’t signal anything to the dog, because it’s located on the dog’s neck. It’s too small to be seen by a human from any distance and, on many dogs, would likely be covered by the dog’s fur anyway.
In the November issue, already in subscribers hands and available at WholeDogJournal.com, we have a number of articles about canine dilated cardiomyopathy (DCM) and diet. The articles are a response to the announcements by the U.S. Food & Drug Administration (FDA) regarding their investigation of possible links between certain types of diets and the development of the disease in what seems like a growing number of dogs.
No statistics are kept about
the rate or prevalence of DCM in dogs, but veterinary cardiologists first
raised their concern that the disease might be occurring more often, and even
more distressingly, in breeds that are not known to be at an increased genetic
risk. They sent reports about their cases to the FDA, who began investigating.
The agency apparently thought the matter merited extra attention or alertness
from pet owners and veterinarians, and, in hopes of increasing awareness of the
symptoms of the disease, they issued their first announcement in June 2019.
More DCM Cases, or Increased Awareness?
The number of cases of any
suspected health condition will rise upon news about its potential risk – and
it does seem that there has been an increase in the number of cases since
awareness of the symptoms of DCM have been widely publicized. I’ve been
following a number of Facebook groups for owners of dogs who have been
diagnosed with DCM, and daily, there
are people who post stories about their dogs – dogs who were newly
diagnosed, dogs undergoing treatment, and dogs who passed away. But, dang, it’s
frustrating to not have any idea whether the incidence of the disease really
has increased or if it only seems so because more people are aware of the
symptoms and are seeking veterinary attention for symptoms that, previously, might
have been mistaken for “old age” and gone undiagnosed.
But, as I said in the editorial
in the November issue, another thing that makes me crazy is the number of
accounts that I read that lament how much they trusted the maker of the very
expensive dog food they were feeding their dog – they fed it for years and
years, and are now angry that the food may have contributed to the dog’s
disease. I don’t think anyone should
trust any company with the sum total
of their dog’s nutrition for years on
end!
What Does This Mean For Your Dog?
It’s important to keep in mind that even the companies whose products have been named in the FDA’s reports most frequently haven’t knowingly done anything wrong. The products have met the existing standards for nutrition, and they have not been contaminated with something that causes illness. No one has identified the cause or causes of the problem, so it’s not like the companies have failed to do something they were supposed to do. There is something – or, more likely, a few things – going on with some foods and/or ingredients.
The solution isn’t just avoiding those foods; until we know more, the solution is not feeding any food as your dog’s sole source of nutrition for years on end. If there is one thing that should be easy for us to do, it’s to switch foods at least a few times a year. Call it a hedge, call it “balance over time,” call it a hassle – whatever you call it, unless your dog is intolerant of many different ingredients, it shouldn’t be that difficult to buy a different product from a different company every other time you buy food. For most dogs, the more often you change their foods, the more robust their ability to digest different foods will become.
To continue reading this article or issue you must be a paid subscriber. Sign in
If you are logged in but cannot access this content, a) your subscription may have expired; b) you may have duplicate accounts (emails) in our system. Please check your account status hereorcontact customer service.
Immediate access to this article and 20+ years of archives.
Recommendations for the best dog food for your dog.
Dry food, homemade diets and recipes, dehydrated and raw options, canned food and more.
Brands, formulations and ingredients all searchable in an easy-to-use, searchable database.
Plus, you’ll receive training and care guidance to keep your dog healthy and happy. You’ll feed with less stress…train with greater success…and know you are giving your dog the care he deserves.
Subscribenow and save 72%! Its like getting 8 issues free!
Food reviews have been a standard feature of WDJ for 22 years, so it’s not a surprise we are asked for dog food recommendations. The inquiries multiply whenever there is any bad news about dog food – and the ongoing mystery about a possible connection between dog diets and a serious heart disease, canine dilated cardiomyopathy (DCM), is definitely bad news.
Depending upon which news outlets you follow, you may be worried about feeding your dog a food that is grain-free, one that contains peas or other legumes, or one that is “boutique” or made with “exotic” ingredients.
If you haven’t been following any of the news, you can catch up by reading our in-depth article by nutrition writer Linda P. Case in the September 2018 issue (“The Heart of the Matter”) and the blog posts on August 2, 2018 (“Please Don’t Panic About the Grain-Free Thing”), August 9, 2018 (“Choosing Dog Foods After The Grain-Free Scare”) and July 16, 2019 (“Update on grain-free diets and DCM cases in dogs”). Suffice to say here that in July 2018, the United States Food & Drug Administration (FDA) announced that it was looking into reports of a possible link between DCM in breeds of dogs that are not considered at genetic risk of the disease and diets containing “peas, lentils, other legume seeds, or potatoes as main ingredients.”
A year later, the FDA published an update to its original announcement, which included detailed data about the cases they were investigating but still offered no guidance regarding how owners could feed their dogs in order to protect them from developing DCM.
We have been analyzing the data that has been released about the diets that were named in the 515 reports being investigated by the FDA. From this analysis, we have developed recommendations that can help you make feeding choices that we believe could protect your dogs from this disease. In the online version of this article, we have included links that will take you to more detailed explanations, should you wish to know more about how we came to our conclusions.
Before we go on, though, please note: Anything you read, including here and in articles written by veterinary nutritionists, is conjecture. No one knows for sure what might explain a link between certain types of diets and DCM in some dogs – or whether there even is a link – although we believe there is.
Is Your Dog at Risk?
It’s important to keep in mind that the vast majority of dogs who are fed the diets named in the FDA’s reports do not develop DCM! On the other hand, we know that there are more cases of DCM than those that have been reported (or even diagnosed). So how concerned should you be?
The risk of diet-related DCM is not the same for all dogs. Certain breeds of dogs (or lines within breeds) are susceptible to DCM due to taurine insufficiency, where the amount of taurine (or its precursors, methionine and cysteine) in the diet is enough for most dogs, but not for them. These breeds include the American Cocker Spaniel, English Setter, Golden Retriever, Labrador Retriever, Newfoundland, and Saint Bernard. If your dog belongs to one of these breeds, then you should be more concerned about what you’re feeding than the average pet owner.
[post-sticky note-id=’404562′]
Other breeds are genetically prone to DCM that is not linked to taurine deficiency, including Boxers, Doberman Pinschers, Great Danes, and Irish Wolfhounds. These dogs may be at no greater risk of diet-related DCM, but since we don’t know for sure, owners may want to be more cautious with these breeds than with others.
Large and giant breed dogs are more susceptible to DCM than smaller dogs are. If you have a large dog, you should be more concerned about what you feed than those with small dogs. One of the factors that drew the attention of veterinary cardiologists, however, was seeing DCM in some smaller dogs as well, so even people with small to medium dogs may want to take precautions. Dogs who eat less than would be expected for their size (older or inactive dogs, or those who get too many calories from treats) also may be at increased risk of dietary insufficiencies, including taurine, which might help explain why some small dogs are affected.
Another risk factor is dogs who eat the same food for long periods of time. The initial FDA report stated, “Early reports from the veterinary cardiology community indicate that the dogs consistently ate these foods as their primary source of nutrition for time periods ranging from months to years [emphasis ours].”
The longer you feed the same food, the more likely your dog is to be affected by any nutritional deficiencies or excesses it contains. Those who rotate foods regularly, particularly those who rotate between different brands of foods with different primary ingredients, have less cause for concern than those who always feed the same food to their dogs.
Focus on Taurine
All of our recommendations are based on the assumption that the issue linking diet and DCM is related to taurine deficiency. There are two very good reasons for this. The first is the link between taurine and DCM in cats that was discovered in the 1980s. The second is the link between taurine and DCM in certain dogs being fed lamb and rice diets that first came to light in the 1990s. Because we know that a lack of sufficient taurine or its precursors can cause DCM in otherwise healthy dogs of all breeds and mixed breeds, it appears to be the most likely culprit in this current situation.
Some of the affected dogs in the FDA reports were found to have low blood taurine levels; however, the majority have normal blood taurine levels. Despite this, most dogs diagnosed with what is suspected to be diet-related DCM are given taurine supplementation, regardless of their taurine blood levels, as well as being switched to a different diet and prescribed heart medications. Some dogs improve, others do not. At this time, it’s impossible to know which factors lead to improvement and which are unnecessary.
Until we know more, our recommendations center on avoiding taurine deficiency by increasing the bioavailability of taurine and its precursors, even for dogs who do not appear to be taurine-deficient.
In general, we recommend avoiding the potential at-risk food categories identified below, or at least limiting them to less than half of your dog’s total diet (if you feed more than two types of food). If you cannot avoid these food categories, then we recommend that you look for foods with added taurine, and/or consider supplementing your dog with taurine yourself (see Supplementing Taurine, below), particularly if your dog is at higher risk of developing DCM, as described above.
We identified 293 different foods in the 515 reports being investigated by the FDA. We looked at the ingredients and guaranteed analysis of each of these foods, and, just as the FDA’s researchers were no doubt doing, looked for patterns or categories of products to study separately.
[post-sticky note-id=’404565′]
We identified four categories of products that might be linked to DCM in at least some dogs. All four start with the letter “L,” which can help to remember them.
Legumes. The FDA reported that 93% of all products involved in the reports they were investigating contained peas and/or lentils. Our analysis confirmed that 89% of the reported foods appeared to contain significant amounts of these ingredients (generally appearing before the first fat or in multiple combinations, sometimes with other legumes).
Lamb. Lamb-based diets are a known risk factor for taurine-deficient DCM. Our analysis found that more than 20% of the foods named in the FDA’s reports were lamb-based.
Limited-ingredient. We were a little surprised to find that limited-ingredient diets were also overrepresented in these reports and we therefore consider them another potential risk factor.
Low-protein. Diets with low protein levels are a known risk factor for DCM. Normal-protein diets that rely on plant proteins, such as from legumes, also appear to pose a higher risk.
Let’s look at each of these “L” food categories of concern.
Legume-rich diets
The FDA found that the vast majority of reported products (93%) contained peas and/or lentils. It seems likely that something about peas and lentils is impacting the availability of taurine or its precursors in the body. This could be due to incomplete plant proteins replacing animal proteins, or fiber from peas and lentils blocking absorption of nutrients, or some other anti-nutritional factors we don’t fully understand.
Peas are a relatively new ingredient whose popularity has exploded in the last 10 years. The fact that so many foods today contain significant amounts of peas (and other legumes) and the increase in the number of dogs that are reportedly developing DCM (especially those in categories not typically associated with this disease) seems significant. Remember, however, that correlation does not equal causation; again, we are speculating, as no one knows the cause at this time.
Legumes are defined as plants whose fruit (seeds) is enclosed in a pod. Legumes found in dog food include peas, lentils, beans (e.g., pinto beans, navy beans, kidney beans, lima beans, fava beans) and chickpeas (garbanzo beans). Pulses, another term commonly used, are the dry, edible seeds of plants in the legume family, including dried peas, beans, lentils and chickpeas. All pulses are legumes but not all legumes are pulses. Because dog foods may contain fresh peas as well as dried, we use “legumes” rather than “pulses” to define this category.
[post-sticky note-id=’404560′]
Pulses are high in protein and fiber and low in fat. High-fat legumes such as soybeans and peanuts do not appear to be involved in the DCM issue.
Bottom line on legumes: We recommend avoiding diets with legumes listed high in the ingredient list (before the first fat or oil) or that include several legumes, even if they appear lower in the ingredient list. If you do feed such a diet, it should not have any of the other “L” traits (be lamb-based, limited-ingredient, or contain less than about 30% protein on a dry matter basis [27% as fed, per the guaranteed analysis, for dry foods]). If you feed high-legume foods as a major part of your dog’s diet, look for foods with added taurine, or consider supplementing with taurine yourself.
[post-sticky note-id=’404567′]
Lamb-based diets
Nutritionists have known for more than 20 years that certain breeds of dogs were prone to developing DCM when fed lamb and rice diets. Studies indicate this likely has to do with low bioavailability of taurine’s precursors, methionine and cysteine, in lamb meal. Responsible companies began adding taurine to their lamb and rice diets long ago.
Our analysis of foods named in the FDA reports found that more than 20% of these reports involved diets where lamb was the primary meat source; this included several of the foods with the most reports. The FDA’s analysis found lamb was the second-most common animal protein in reported foods (after chicken). Both of these appear to indicate that lamb is overrepresented in the named foods.
We expect that reliable companies already add taurine to their lamb and rice diets. We also would expect that by now they are in the process of adding taurine to their lamb-based diets that also contain legumes.
Bottom line on lamb: We advise avoiding lamb-based diets without added taurine. If you do feed a lamb-based diet, it should not be high in legumes, limited-ingredient, or low in protein. In addition, we would avoid all foods from any company that sells a lamb and rice diet without added taurine (if they hadn’t already been getting that right, we just wouldn’t trust them at all).
Note: We found several diets where lamb meal was listed second in the ingredient list, following a fresh protein such as beef or bison, which was usually the name used on the label. Because dry lamb meal weighs less than fresh meats, these foods contain more lamb than whatever was named first and would be considered lamb-based diets. Pay attention to ingredient lists, not just the name on the package!
Limited-ingredient diets
The first response from a veterinary nutritionist to the initial FDA report about a possible link between diet and DCM warned against “exotic” ingredients, but her list included both lamb and peas, neither of which would be considered exotic these days (see “We Won’t BEG, below). Instead, what we found was an overrepresentation of limited-ingredient diets, many of which contained no ingredients that most people consider exotic. Almost 40% of all reports received by the FDA involved limited-ingredient diets.
[post-sticky note-id=’404569′]
The great majority of these diets included peas and/or lentils, but since that was true for all foods, not just limited-ingredient diets, it doesn’t explain why limited-ingredient diets were named in such a large percentage of reports.
We do not recommend feeding limited-ingredient diets to most dogs, as we believe feeding a variety of ingredients is more likely to meet your dog’s nutritional needs. If you feed a limited-ingredient diet due to your dog’s severe food allergies or digestive issues, avoid foods high in legumes or that are lamb-based or relatively low in protein.
As a general rule we also recommend that you avoid feeding most exotic proteins, anything other than beef, chicken, turkey, lamb, and maybe fish. Exotic proteins (such as kangaroo, venison, duck, bison, rabbit, and so on) should be reserved for potential food allergy testing and/or treatment in the future.
Bottom line on limited-ingredient foods: Until we know more, we feel that companies that make limited-ingredient diets should start adding taurine to these foods. If you feel you must feed a limited-ingredient diet that does not include added taurine, we would suggest supplementing your dog with taurine.
One additional note: Kangaroo was the protein used in the single food reported most often to the FDA – Zignature Kangaroo Formula. This food had twice the number of reports (44) as the next food, Acana Singles Lamb & Apple Formula (both limited-ingredient diets). While no research has been done that we’re aware of, it would appear that kangaroo, like lamb, may be associated with low taurine bioavailability.
Low-protein diets
Insufficient dietary protein is a known risk factor for canine DCM. Protein is needed to build lean muscle, and since the heart is a muscle, insufficient protein can also affect the heart.
We found only a small number of reports of very low-protein diets linked to DCM, but most had no other risk factors (no peas or lentils, not lamb-based or limited-ingredient). Several low-protein urinary care and renal prescription diets were reported to the FDA as being possibly linked to DCM. These diets range from 10.9% to 18.1% protein on a dry matter basis (10 to 16% as-fed).
In our opinion, these prescription diets are often fed unnecessarily. In particular, we do not recommend feeding low-protein diets such as Hill’s Prescription Diet u/d to most dogs prone to forming urinary stones, or feeding diets designed for dogs with late-stage kidney disease who are not expected to live very long to dogs with early-stage kidney disease, who may live for years.
In addition, when we looked at all the named diets that did not include peas or lentils, we found a higher percentage of lower-protein diets, and some with mid-level protein but also with plant proteins in the ingredients, such as corn and wheat gluten meals, pea protein, and potato protein.
Plant proteins may be used to replace animal proteins, providing less taurine and its precursors and more fiber and other factors that may interfere with taurine absorption. Avoid foods that contain corn gluten meal or wheat gluten meal; these are poor-quality, incomplete plant proteins primarily found in lower-quality foods. Pea and potato protein may be acceptable if far down in the ingredient list, but we don’t believe they offer much if any nutritional benefit (we’d prefer to see added taurine instead).
Bottom line on low-protein: In general, we advise looking for foods with at least 23% protein DM (21% on the label, also expressed “as fed,” for dry foods), and preferably more. If you feed a diet that contains a significant amount of legumes, or that includes beet pulp or plant proteins, increase this minimum amount of protein to about 30% dry matter (27% as fed for dry foods). If you feel you must feed a diet with less protein than this, we advise supplementing your dog with taurine.
Additional recommendations
Beet pulp is known to interfere with taurine absorption. A 2016 study published in the Journal of Animal Science and Technology found that beet pulp may contribute to a decrease in taurine levels in dogs, both because it reduces protein digestibility (and thus the availability of the sulfur amino acids methionine and cysteine, taurine’s precursors) and because it increases fecal excretion of taurine.
Beet pulp is commonly used in dog foods as a source of fiber, but because of its effect on taurine, it would be safest to avoid this ingredient in diets with any of our “L’s” of concern (Lamb-based, Legume-rich, Low-protein, or Limited-ingredient).
The FDA also named potatoes and sweet potatoes as suspect ingredients, but we have our doubts about their potential contribution to diet-related DCM. Both of these ingredients have been used in pet food for much longer than peas and other legumes, and neither is used as an alternative to or replacement source of animal protein.
Our analysis supports this hypothesis: All of the reported grain-free dry foods with significant amounts of potatoes or sweet potatoes also fell into one or more of the other at-risk categories. If these ingredients were truly a risk factor, we would have expected to see many foods reported that contained potatoes or sweet potatoes but did not contain legumes and were not lamb-based, limited-ingredient, or low in protein. At this point we do not feel that the data support avoiding foods that contain potatoes or sweet potatoes.
One ingredient in this category concerns us, however: potato protein. We don’t like to see incomplete plant proteins used to replace better quality, pricier animal proteins, or to inflate the protein percentage on the label.
Remember the four “L’s”
Again, remember that we don’t know for sure if following our guidelines will help your dogs avoid developing DCM, but we believe they are your best option until more is known.
Four types of diets – those rich in legumes (peas, lentils, beans, chickpeas); limited-ingredient diets (especially those that use kangaroo); lamb-based diets; and diets that are low in protein or that rely too much on plant proteins – may be associated with low taurine bioavailability that could lead to DCM, particularly in certain breeds, large dogs, and those who eat less than expected for their size. We believe that limiting how much you feed of these types of diets, and/or supplementing your dogs with taurine, should help keep them safe.
Discusses differing opinions among veterinarians as to the pros and cons of rotation feeding for dogs. Includes quotes from Dr. Joe Bartges, a nutrition consultant at the Veterinary Information Network, and Dr. Paul Pion, one of the veterinarians who first discovered the link between taurine and DCM in cats, supporting feeding a variety of different foods.
Taurine
History of diet-related links between taurine deficiency and DCM
Retrospective study found no correlation between blood taurine levels and dietary taurine in dogs with DCM, and no difference in outcome when both taurine-deficient and nondeficient dogs were supplemented with taurine.
Study found that taurine excretion was more than three times greater for dogs fed a commercial lamb meal and rice diet compared to those fed a poultry by-product-based diet, though blood levels of taurine remained similar in both groups.
An investigation of the taurine status in a group of related Newfoundlands found that the taurine-deficient dogs had been fed lamb meal and rice diets, and that the taurine deficiency was reversed by a change in diet or methionine supplementation.
Cornell University College of Veterinary Medicine April 23, 2014
Case history of a dog diagnosed with DCM after being fed a homemade vegan diet, with other dogs in the same home eating the same diet similarly affected.
Lists additional breeds: American Cocker Spaniels, Golden Retrievers, Newfoundlands, Labrador Retrievers, Dalmatians, English Bulldogs, Portuguese Water Dogs and Irish Wolfhounds
Study done to determine whether the known risk of taurine-deficiency-induced DCM in dogs fed lamb and rice diets is linked to the inclusion of either rice bran or beet pulp. The study concluded that rice bran was not a contributing factor, but beet pulp may contribute to a decreased taurine status in dogs.
Relationship of taurine to the current FDA investigation
An overview of diet-associated DCM, including known information about a link between taurine deficiency and lamb and rice, low-protein, and high-fiber diets, as well as beet pulp. Includes dosage guidelines for taurine supplementation
Study found that 23 of 24 dogs who developed DCM while eating diets that were grain-free and/or legume-rich improved with diet change and taurine supplementation. No difference was found when L-carnitine was supplemented as well as taurine. Measurement of taurine status in dogs yields inconsistent results.
Journal of Veterinary Cardiology Volume 21, February 2019, Pages 1-9
Study compared several factors in 48 dogs with DCM. It found that the dogs fed a grain-free diet were not taurine deficient, yet seven dogs reevaluated after diet change (six received taurine supplementation as well) all showed improvement.
STERN CARDIAC GENETICS LABORATORY, JOSHUA A. STERN, DVM, PHD, DACVIM (CARDIOLOGY) March 4, 2019
Guidelines for veterinarians regarding taurine testing and treatment. Includes dosage guidelines for taurine supplementation, recommended for all dogs with evidence of DCM even if not taurine deficient.
Journal of Animal Science, Volume 97, Issue 3, March 2019, Pages 983–997
Detailed analysis of amino acid guidelines and history suggests that AAFCO requirements for methionine and cysteine should be increased and that taurine requirements should also be considered. Conclusions mention that “final product formulations should be assessed for nutrient balance and bioavailability, especially when using a limited number of ingredients (emphasis ours).”
A discussion of how the amount of peas and other legumes in pet foods has increased, and why relying heavily on peas and other legumes may not be a good idea, three years before the first FDA report was released. Does not discuss DCM.
Pet nutrition researchers suggested taurine supplementation in dog food as a potential, stopgap measure to prevent DCM while scientists search for hard answers, during a panel discussion at Petfood Forum 2019. One new product was positioned to allow dog owners to do just that for themselves. InClover’s BioVibrant Taurine Plus comes in a shaker container like one used for spices. The dog food topper is marketed as providing “the missing piece for peace of mind.”
This article is a sidebar to our post “Diet, Dogs, and DCM”, which appeared in the November 2019 issue
If this is the first you’re hearing about this issue, please don’t panic and immediately switch your dog’s diet, unless your dog is used to eating different foods. Suddenly changing foods is likely to cause digestive upset in dogs that are unused to it. The longer you’ve been feeding the same food, the more likely your dog is to need time to adjust to something different.
Start by replacing very small amounts of the old food with the new. If your dog is doing well, gradually increase the amount of the new food while decreasing the old. This may take just a few days, or up to a few weeks, depending on how long you’ve been feeding the same thing and how sensitive your dog’s digestive system might be.
Stick with new foods that have a similar level of fat to what you’ve been feeding, at least to start with; it’s more likely that a dog will develop digestive issues if switched from a low-fat diet to one that is higher in fat, particularly if the switch is done too quickly or the dog has been on the low-fat diet for a long time.
If your dog is prone to food allergies, it’s likely he will react quickly with itching and scratching if you feed an ingredient that he’s allergic to. Digestive upset may point toward a food or fat intolerance, or may just be the result of trying to switch too quickly; if your dog vomits or has diarrhea, go back to the old diet until he’s back to normal, then try the switch once more, going even more slowly the second time. If your dog continues to have digestive upset with that food, try something else. Keep a journal of which foods you try and the ingredients in each, and you may be able to pinpoint the ones that cause problems for your dog.
If you have been feeding a limited-ingredient diet because your dog tends to have either allergic (itchy) reactions or digestive upset with other foods, here’s what we would recommend. Start by feeding another food in the same line of foods, so that only the protein source changes. Keep track of which proteins your dog has problems with, and which he does well with. Once you know which proteins your dog can tolerate, try another brand of limited-ingredient diet with a protein your dog is okay with. Continue trying different proteins from the same lines, and different brands of foods using those proteins to get a better idea of which ingredients cause problems for your dog. Once you’ve identified the actual ingredients that your dog has trouble with, you can then try branching out into other foods that are not limited-ingredient diets.
We know that many people feed the same food to their dogs all the time because it’s easier, or because they think it’s better (since that’s what dog food companies and many vets recommend), or because they tried a different food once or twice and their dog didn’t like it or didn’t do well on it. In these cases, we still recommend trying to switch your dog to a different diet, or preferably multiple diets using different brands of foods and different primary ingredients. We still believe that this approach is not only more likely to prevent DCM, but also helps prevent food allergies from developing, and provides protection against any nutritional deficiencies or excesses found in any single diet, as well as issues that lead to recalls.
For those who feed a rotational diet, we advise restricting foods in at-risk categories to less than half the overall diet. That means if you feed just one or two foods, neither should be in any of the at-risk groups we describe. If you feed three or four different foods, one can be among the at-risk categories. If you feed five or six different foods, two can be among the at-risk categories. Foods that fit into more than one of the at-risk categories are likely to be a higher risk than foods that fit into just one; the more categories a food fits into, the higher the potential risk. At least half the foods you feed should have: common meats such as chicken, turkey or beef (not lamb), multiple (not limited) ingredients, little or no legumes, and moderate to high protein.
This article is a sidebar to our post “Diet, Dogs, and DCM”, which appeared in the November 2019 issue
Some people will be upset that we didn’t name all 293 foods that have been reported to the FDA as being possibly connected to DCM. Those people think that if they could just see the list of named foods, they could avoid those and feel safe feeding anything else, but that’s simply not the case. Just because a food was named does not mean it should not be fed, particularly if there were only one or two reports for that food, or if the food has been reformulated or added taurine since the reports were made. We have no way of knowing how valid the reports might be; it could be pure coincidence that a dog developed DCM while eating this food, particularly in breeds known to be genetically prone to DCM, or maybe the dog was recently switched to that food, so it wouldn’t have had time to cause heart problems.
Conversely, just because a food is not named does not mean it is therefore safe to feed. Only a small percentage of suspected cases ever get reported to the FDA, and the likelihood of reports goes down for foods that have a small market share or are new to the market. The list of reported foods is also a moving target: not only will there continue to be more reports, but companies are likely to change the formulations or the names of their foods over time, so that the food currently on the shelf is no longer the same as the food that was reported, or a reported food has the same formulation but a different name. Looking for names is not going to help; knowing what to look for in ingredient lists is far more important.
With that said, there were a few foods that were reported so frequently that, even though they met AAFCO guidelines, we suspect they all contributed in some way to the development of DCM in some dogs. We are going to provide those names, though most now contain added taurine (and we applaud the manufacturers for doing so). We will also show the major ingredients in each food at the time of the reports, to the best of our ability (it is not always possible to know when an ingredient list changed). Below, you will find the seven products that were mentioned most frequently in the reports, with the factors that may be linked to DCM in bold type.
Note: In its June 2019 Update, the FDA provided a chart that listed the 16 companies with the most products listed among the reports it was investigating to date. No information was provided as to which of the foods made by those companies were the ones that were associated with the reports. In our view, this may have been unfairly damaging to certain companies, and offered consumers no information as to which products may have been free of mentions in the reports. We were more interested in trying to figure out which products had the most mentions in the reports, and what they had in common.
(44 reports) Zignature KangarooLimited Ingredient Formula (dry):
Old formula: Kangaroo, Kangaroo Meal,Peas, Chickpeas, Pea Flour, Sunflower Oil (preserved with Citric Acid), Flaxseed, Red Lentils, Green Lentils, Dehydrated Alfalfa Meal, Pea Protein, Natural Flavors, Salt, . . .
Guaranteed Analysis: minimum 26% Protein
Product has added taurine and been reformulated since the first FDA report was released.
In total, Zignature had 12 foods named in a total of 77 reports (33 in addition to the dry Kangaroo Formula). The most named formulas other than Kangaroo were Turkey Formula (6), Lamb Formula (5) and Trout & Salmon Meal Formula (5), all dry foods. Three reports were for canned foods. All Zignature formulas are high in legumes and limited-ingredient. The guaranteed analyses show minimum protein ranging from 26-32%, with the Kangaroo Formula having the lowest protein percentage. The company states that they began supplementing all of their diets with taurine after the FDA reports were released.
(22 reports) Acana Singles Limited IngredientLamb & Apple Formula (dry):
Product has added taurine and been reformulated since the first FDA report was released.
In total, Acana had 18 foods named in a total of 78 reports (56 in addition to the Lamb & Apple Singles Formula). The most named formulas other than Lamb & Apple were Pork & Squash Singles (11), Duck & Pear Singles (8), Heritage Freshwater Fish (5), and Heritage Free-Run Poultry Formula (4). A total of 43 reports were for the Singles (limited-ingredient) line of foods, followed by 16 reports for the Heritage line and 10 for the Regionals line. All reports were for dry foods (Acana does not make canned foods). All reported Acana formulas are high in legumes; all Singles formulas are limited-ingredient. The guaranteed analyses show minimum protein ranging from 27-35%, with a discontinued Singles Formula (Wild Mackerel) having the lowest protein percentage. The company states that they reformulated their Singles foods, adding more meat and taurine supplementation, in September 2018.
Lamb Meal, Peas, Tapioca, Canola Oil (preserved with Mixed Tocopherols), Pea Protein, Pea Fiber, Flaxseed, Natural Flavors, Blueberries, Cranberries, Apples, Carrots, Spinach, Salt . . .
Guaranteed Analysis: minimum 26% Protein
No changes that we’re aware of since the first FDA report was released but already included added taurine.
In total, Earthborn Holistic had 5 foods named in a total of 37 reports (19 in addition to Meadow Feast). A total of 43 reports were for the Singles (limited-ingredient) line of foods, followed by 16 reports for the Heritage line and 10 for the Regionals line. The most named formulas other than Meadow Feast were Coastal Catch (8), and Great Plains Feast (4). All reports were for grain-free dry foods. All reported Earthborn Holistic formulas are high in legumes. The guaranteed analyses show minimum protein ranging from 25-32%, with Meadow Feast having one of the lowest protein percentages. The company states that they have always fortified their grain-free recipes with taurine and other amino acids. Earthborn Holistic is a Midwestern Pet Foods brand.
(12 reports) California Natural Kangaroo & Red Lentils Recipe, Grain Free Limited Ingredient Diet (dry):
Kangaroo, Red Lentils, Green Lentils, Peas, Sunflower Oil, Flaxseed, Pea Fiber, . . .
No changes that we’re aware of since the first FDA report was released; does not contain taurine according to the ingredient list on the Costco website.
In total, Kirkland Signature had 7 foods named in a total of 34 reports (22 in addition to Salmon Meal & Sweet Potato Formula). A total of 5 foods and 32 reports were for the Nature’s Domain line. The most named formulas other than Salmon Meal & Sweet Potato were Nature’s Bounty Organic Chicken & Pea (8), and Nature’s Bounty Turkey Meal & Sweet Potato (3). All reports were for dry foods (Kirkland Signature does not make canned foods). All reported Nature’s Domain formulas are high in legumes. The guaranteed analyses show minimum protein ranging from 20-27%. There is no indication that the company is making any changes to their foods. Kirkland Signature is a Costco brand but the Nature’s Domain line is also available elsewhere.
Product has added taurine since the first FDA report was released.
In total, Taste of the Wild had 11 foods named in a total of 63 reports (52 in addition to Pacific Stream). A total of 5 foods and 32 reports were for the Nature’s Domain line. The most named formulas other than Pacific Stream were High Prairie (10), Sierra Mountain (6), Pine Forest (6), Prey Angus Beef Limited Ingredient Formula (5) and Prey Trout Limited Ingredient Formula (5), with an additional 12 reports for unspecified grain-free formulas and 3 reports for unspecified Prey limited-ingredient formulas. All reports were for dry foods. All reported Taste of the Wild formulas are high in legumes; all Prey formulas are limited-ingredient. The guaranteed analyses show minimum protein ranging from 25-32%. The company states that they began adding taurine to recipes without grains after the initial FDA report was released.
Unhappy face when told "stay" at a sit, looks away.
I was teaching a “teen dog” class last night, and we were
working on the “stay” behavior. In the training center where I teach, we
instruct the students on the “four Ds” of stay – distance, duration,
distraction, and disappearance (the last one, very advanced, when the handlers
can leave the room and their dogs will “hold” the stay). We teach that when you
increase the difficulty of one of the “Ds,” you should decrease the others –
so, in the high-distraction environment of the training center, with eight dogs
in the class, to help your dog succeed, you should reduce the distance and
duration of the stay you ask of your dog. So far, so good.
As the handlers and their dogs practiced, I noticed one dog
doing exactly what my younger dog, Woody, does when we work on the stay
behavior. Every time this dog’s handler gave the hand signal and verbal cue for
“stay,” his dog turned her head away, jumped to her feet, and looked around for
something else to do. Clearly, there is something about the stay behavior that
she found either aversive or perhaps just far less rewarding than the other
behaviors we practiced in class.
Woody Doesn’t Like the Stay Cue
In Woody’s case, he loves doing all the “action” sort of behaviors I might ask him for: sit, down, stand, back up, spin, go through my legs. And he enjoys the eye contact that we usually share while we are working on these behaviors. But, just as the dog in class last night, often, when I cue him for “stay,” his head will immediately swivel and he will look away, like, “Did I just hear the doorbell? Maybe I should go check!”
Unhappy face when told “down stay”
As an active dog, I think Woody finds the stay behavior
extremely boring – and what’s more, it’s more difficult for him to do than the
far more fun, active, exuberant behaviors. Not difficult physically – difficult
mentally. To counter this, and keep
solid stays, I really need to increase the quality and quantity of the rewards
he gets for good stays, keep the length of the behaviors extremely
unpredictable (if they are all long, no reward is good enough to make it worth
his while!), and not over-practice. This is one of his behaviors that gets worse with more practice, not better,
since he finds it to be extremely not
fun.
Resist the Urge to Over-Practice!
It’s human to want to keep practicing the behavior your dog
is not very good at – especially when she’s really good at almost every other
behavior you ask for! But resist that urge! – unless you can find a way to
change how you ask for or practice the behavior, so that your dog actually
loves to hear your cue for that particular behavior. Woody loves to come find
me when I hide, so I guess I will start cueing him to “stay” before I release
him to find me (with a whistle, from my hidden location). I hope that will
increase his interest in and desire to “play” the “stay” game.
Are there any behaviors that your dog hates being asked to
do? How can you tell he or she doesn’t enjoy it? How have you countered your
dog’s unhappy reaction to the cue?
This evening I was relaxing, scrolling through the news online and checking out dog pictures and videos on social media, when I came across a story that just made my blood run cold. It was posted by an acquaintance who lives one town away from me, and detailed how her husband had gone out that morning for a jog with their Australian Shepherd Zazu; they take a six-mile run together on-leash, four days a week. One this morning’s run, however, not a block from their home, Zazu was attacked by two Rottweilers, who were loose, with their owners nowhere to be seen.
The police were summoned,
the dogs caught and impounded, Zazu rushed to the emergency veterinary
hospital, but his wounds were too serious and he could not be saved. A
neighbor, who heard the tumult and witnessed the scene, identified the dogs as
belonging to a couple who lives nearby. They are older, she told the police –
and one of their adult children who also lives there breeds the dogs and sells
puppies for extra income. Usually, the dogs are never taken out of the yard – but they do get loose from time to
time.
Loose dogs in the neighborhood
Personally, I don’t think
there is a place in society for dogs who kill. And while no one is perfect, and
everyone has had a dog who has gotten loose before, when you own large, powerful
dogs (especially more than one), you have a greater-than-average responsibility
to see to it that your dogs can not escape the security of your yard. I hope
the owners of these dogs are held responsible for Zazu’s death, and I hope the
dogs who murdered Zazu are not released back into the custody of their owners –
or, perhaps anyone else.
I know that’s harsh. It’s not the dogs’ fault that they were inadequately contained. It’s not their fault that their owners failed to socialize them adequately, so that they saw a leashed dog as prey or an interloper in their neighborhood, as opposed to a potential playmate. It’s not their fault that they have been denied the stimulation of an active dog like Zazu, locked up with no exercise, reduced to a life of breeding and reproduction, over and over.
It’s not fair. But it’s not fair to Zazu and his owners, either, that two very powerful, aggressive dogs were in a position to kill. What if the dog they attacked had been being walked by an elderly or frail person? The person might be dead, too. What if the dog they attacked was being walked by a mother who also was pushing a stroller with a baby inside? I shudder to think of it.
People who keep dogs in a socially
impoverished environment, for the sole pupose of breeding puppies to sell –
that’s even worse. This type of person is literally the backyard breeder in the
derogatory trope.
I am hoping that the dogs are designated
as dangerous and steps are taken to make sure they can’t be a threat to anyone
else in the community. And my heart goes out to the owners of poor Zazu; his
dad will be forever traumatized by the memory of the TEN MINUTES he struggled
to save his dog as Zazu was being fatally mauled.
What steps can Zazu’s owners take?
Zazu with his owner
I asked someone I know who is an animal
control officer in a different community: What should Zazu’s owners do? She
said, if there is any kind of record of the dogs being loose before, or any
previous complaint made about their aggression, the local animal control could
take steps to get a dangerous dog designation for the Rottweilers. If there is
any sort of record of the dogs doing this before, or even just being picked up
for running loose before, she would press the local court for the dangerous dog
designation.
But if this is the first record of any complaint about the dogs, then their owners are likely to be fined only for the dogs “running at large,” asked for proof of licensing and rabies vaccination (and possibly fined for lack of same), and charged for the short impound; all that Zazu’s owners can do is sue for Zazu’s final vet bill, including cremation.
Obviously, I love dogs, and don’t relish the idea of any dogs being euthanized. But large, aggressive dogs in the hands of owners who can’t or won’t contain them? I can’t imagine living and walking my own dogs in that neighborhood.
Do any of you have any advice for Zazu’s owners? Have you ever been in a situation like this?
WDJ Editor Nancy Kerns and a Poodle puppy from one of those many childhood litters, circa 1970.
I grew up in a family that loved dogs. Each of us four kids
had our “own” dog at some point growing up, and we also had some dogs who were
just indiscriminately part of the family, belonging to no one in particular.
The high point of the family’s dog ownership – or perhaps low point, the way I
see it as a responsible dog owner today – came during the years when I was
about five to 10 years old. During that period of time, I can safely say we
always had at least five adult dogs
(the number changed frequently). And in the year that I was about 7, we had
three different females who all had litters of puppies within a few weeks of
each other. Puppies were everywhere! I was in heaven!
For perspective, that was 1970. Spay/neuter surgery was
unheard-of. We lived in a rural area in Northern California, and our dogs slept
outside (with a few exceptions for the purebred miniature Poodle and a male and
a female Cocker Spaniel we owned for a time) and mostly ran free – meaning, not
one of my childhood dogs lived into anything like old age. Many died after
being run over by cars. That seems outrageous today, but it was normal then.
Most of my childhood friends had also lost dogs because they had been hit by
cars. (It was so common that veterinarians used an acronym for it: HBC.)
My dogs were my buddies.
I was the youngest of the four kids in my family by five
years, which meant that when I was 7, my siblings were 12, 13, and 14. None of
them wanted to hang out with me! And the closest kids my age lived a mile away!
So, it was dogs who kept my childhood from being really pretty lonely, although I never would have recognized any of that as truth at the time. What I did know is that the dogs were always there for me, always ready to play a game, snuggle, or go exploring with me. They were there when my feelings were hurt by the rejection of my exasperated older brother and his friends (there were a lot of boys his age who lived close to us, he had plenty of friends to choose from). They were there when my parents were loudly fighting about something (now I can understand; my parents were so young! And with that many kids – and dogs! – money was always tight). They waited with me (at the roadside!) for the school bus in the morning, gleefully ran to greet my school bus in the afternoon, and on days with no school, kept me company all day long.
Share your story
Which is why this
video resonated so much with me. Made by a wonderful organization (Pets Add Life) whose only purpose seems to
be to promote the adoption of pets from shelters, it brought me right back to
why I connected so much with dogs when I was a kid – a connection that has
continued through to today. Whose dog has not
soaked up some tears or joined in a celebratory dance?
Share the story of what your dog has gotten you through –
and share the video! If you follow the link
to the website, it points you to adoptable animals in your area –nice!
To continue reading this article or issue you must be a paid subscriber. Sign in
If you are logged in but cannot access this content, a) your subscription may have expired; b) you may have duplicate accounts (emails) in our system. Please check your account status hereorcontact customer service.
Immediate access to this article and 20+ years of archives.
Recommendations for the best dog food for your dog.
Dry food, homemade diets and recipes, dehydrated and raw options, canned food and more.
Brands, formulations and ingredients all searchable in an easy-to-use, searchable database.
Plus, you’ll receive training and care guidance to keep your dog healthy and happy. You’ll feed with less stress…train with greater success…and know you are giving your dog the care he deserves.
Subscribenow and save 72%! Its like getting 8 issues free!
The frequent sites of melanoma in dogs include the eyes, mouth, skin and toes.
Canine melanoma is the umbrella term for a group of melanocytic tumor subtypes that are so complex and diverse (yet distinct from each other) that they can sometimes seem as if they are different diseases entirely. What all types of melanomas do have in common is that they form when normal melanocytes (cells that are responsible for producing melanin) divide and grow out of control.
Melanomas are classified as either benign or malignant tumors. Fortunately, the majority of melanomas that occur in dogs are benign; this form of melanoma is typically referred to as a melanocytoma. These tumors are not cancerous and usually do not become cancerous, nor do they interfere with the function of normal cells. They will often cease growing once they reach a certain size and they do not invade other tissues. Furthermore, they do not metastasize, and they tend to not grow back when surgically removed.
In contrast, malignant melanomas, accounting for 5 to 7% of all canine melanomas, are highly aggressive and can metastasize to vital organs very quickly. About 100,000 cases of malignant melanoma in dogs are diagnosed in the U.S. each year.
This cancerous tumor tends to form in areas of the body that are pigmented, and while the tumors are usually brown or black, they can appear pink, tan, or even white, depending on the level of melanin being produced. These are most commonly seen in middle-aged to older dogs (average age of 9 years) with no gender predilection.
The location in the body will determine the specific biological behavior of this cancer. Dogs are often asymptomatic until the cancer has spread.
Causes of Melanoma in Dogs
The etiology of canine melanoma is not known, but researchers believe that it may due to a combination of environmental factors and genetics. It is also suspected that chemical agents, stress, trauma, or excessive licking of a particular spot could be factors; if cells are triggered to randomly multiply, it can increase the chance of mutation during cell division and result in the formation of malignant cells.
While ultraviolet light exposure is a major cause of melanoma in humans, it is not usually associated with the canine form due to their protective coat of fur.
Breed Disposition
Malignant melanoma in dogs is thought to reflect a strong genetic component with the following breeds being over-represented: Airedales, Bloodhounds, Boston Terriers, Chihuahuas, Chow Chow, Cocker Spaniels, Dachshunds, Doberman Pinschers, English Springer Spaniels, Golden Retrievers, Gordon Setters, Irish Setters, Pekingese, Poodles, Rottweilers, Miniature and Giant Schnauzers, Springer Spaniels, Scottish Terriers, and Tibetan Spaniels.
The disease is also more likely to appear in the toes or toenail bed of black dogs; small breeds with heavily pigmented mucous membranes in the mouth are reported to be at an increased risk of oral melanoma.
Diagnosis
Diagnosis of canine malignant melanoma is typically obtained through cytology from a fine-needle aspirate of the tumor and/or biopsy and histopathology, but they are also known for being challenging to diagnose.
When melanomas are pigmented, the pathologist can usually see the melanin granules and characteristic cell morphology in the sample. Difficulties arise when melanocytic tumors lack pigmentation and the cell morphology varies tremendously.
The histopathological results of the biopsy may resemble carcinoma, sarcoma, lymphoma, or an osteogenic tumor. At this point, additional testing with special stains for immunohistochemical (IHC) markers (Melan-A, PNL-2, tyrosine reactive protein TRP-1 and TRP-2) is required; this screening is highly sensitive and specific for detecting melanocytes. It is vital to have an accurate diagnosis as that will determine the treatment protocol used and the prognosis.
Further diagnostic tests to assess the dog’s overall health and determine the stage of the disease may include a complete blood count; serum biochemical profile; urinalysis; chest radiographs and abdominal ultrasound to look for evidence of metastasis; and lymph node aspirate to check if cells have spread to the lymphatic system.
In dogs with the oral form of melanoma, especially if the lymph nodes are noted to be enlarged, further testing is warranted to check for metastasis in the abdominal lymph nodes, liver, adrenal glands, and other sites.
For oral tumors, radiographs and/or a computed tomography (CT) scan may be recommended.
Because digital (toe) melanoma often involves bone destruction, radiographs should be taken of the affected foot.
Specific diagnostic techniques for ocular melanoma involve slit-lamp examination, tonometry (intraocular pressure), gonioscopy (exam of the front part of the eye), and fundoscopy (exam of the back of the eye).
Stages of Melanoma in Dogs
The diagnostic tests discussed above will provide the foundation for assigning a stage and grade to the patient’s malignant melanoma.
Oral malignancies. For these tumors, staging is fairly straightforward and extremely prognostic. While the World Health Organization’s staging system is considered limited in its application (tumor size is not standardized to the size of the patient and histologic appearance and other histologic-based indices are not considered), it is often still used:
Stage I: Size of primary tumor is less than or equal to 2 centimeters (cm) in diameter with no involvement of lymph nodes.
Stage II: Size of primary tumor 2 to 4 cm in diameter with no involvement of lymph nodes.
Stage III: Size of primary tumor greater than or equal to 4 cm in diameter and/or metastasis to lymph nodes.
Stage IV: Tumor of any size with distant metastasis present.
Alternative staging systems incorporating histologic criteria have been explored, and while a comprehensive approach has unfortunately yet to be developed, these investigations have continued to find that size and location are extremely relevant.
Non-oral melanoma. The staging system for non-oral forms of canine melanoma is not well defined and further development with clinical variables and outcome is needed.
Histopathologic Grading
There are three histologic features that can be discerned from a biopsy that have been shown to have predictive value. The first, nuclear atypia, is the abnormal appearance of the nucleus of a cell and is considered an indicator of malignancy.
There are several approaches that can be taken to estimate the extent of nuclear atypia, but the assessment is subject to inter-observer variation. It is typically reported as mild, moderate, or severe. Levels greater than or equal to 30% for oral melanomas and greater than or equal to 20% for cutaneous and digit are considered to have poor prognoses.
The second, Ki-67 index, is a quantitative reporting of the cells that are positive for containing the protein Ki-67. This protein increases when cells prepare to divide, and it can be measured with a special staining process. A higher number of positive cells indicates that they are dividing and forming new cells quickly. A Ki-67 proliferative index of greater than or equal to 15% is considered a negative prognostic factor for cutaneous and digital melanomas, as is an index of greater than or equal to 19.5% for oral melanomas.
The mitotic index (MI) is the third and most common feature that can be discerned from a biopsy and is used to estimate the course of the disease. The MI measures the percentage of cells undergoing mitosis (cell division); a higher number of cells that are dividing indicates more aggressive disease. An MI of 3 or higher (out of 10) predicts decreased survival, while an MI of less than 3 predicts a more favorable outlook.
In cutaneous and ocular melanoma cases, the MI is the most reliable element for distinguishing malignant from benign tumors.
[post-sticky note-id=’396308′]
Types of Canine Melanoma
In dogs, there are four primary types of melanoma that can occur: oral (anywhere around the mouth or oral cavity); digital/subungal (around the nail bed and in, on, and between toes); cutaneous (skin); and ocular (in and around the eye). Each type has its own clinical presentation and biological behavior.
Oral Melanoma
This dog has oral melanoma. Photo credit: Eileen Fatcheric, DVM
Melanomas in and around the mouth are considered the most common oral malignancies that occur in dogs. It is estimated that this cancer accounts for anywhere from 14 to 45% of all oral tumors and 80 to 85% of all malignant melanomas.
This form of melanoma typically occurs in dogs ages 10 years and older and in smaller dogs; dogs with heavily pigmented mucous membranes are at higher risk. Tumors can occur anywhere in the oral cavity and surrounding areas, with the majority found in the gingiva/gums. The next most common site is the lips, and then the hard and soft palate. Fewer than 5% develop on the tongue.
The veterinarian is pointed to the cancerous mass in this example of oral melanoma in a dog. Photo credit: Eileen Fatcheric, DVM
Growths tend to be solitary, appearing as a distinct lump or as a flat plaque-like lesion that may or may not be ulcerated. Tumor colors may vary from black to gray to pink or with varied coloring; up to 33% have no pigment at all. Symptoms can include facial swelling; bad breath/mouth odor; abnormal breathing sounds; difficulty chewing, eating, or swallowing; loose teeth; bleeding from the mouth; excessive salivation; and weight loss.
Malignant oral melanomas are quite locally invasive, often infiltrating nearby tissue and bone. At the time of diagnosis, 57% of cases have radiographic evidence of bone involvement. The likelihood for metastasis is high (80 to 85%) with the most common site being the regional lymph nodes, followed by the lungs and other distant organs.
Digital (Toe) / Subungal (Nailbed) Melanoma
Dobermans are one of the breeds that have an increased genetic predisposition to developing melanoma. This dog had a malignant digital tumor, but recovered well after his toe was surgically removed. Photo by Dr. Catherine Ashe
This is the second most common type of malignant melanoma diagnosed in dogs, accounting for 15 to 20% of all melanoma cases and 11% of all tumors involving the digits.
Local invasion is a common feature of this form, with many dogs having evidence of bone damage. Anatomically, the forelimbs are slightly more likely (57.1%) than the hindlimbs (42.9%) to develop a melanocytic tumor.
Dogs with black coats tend to have a higher incidence of the disease. It tends to present as a solitary tumor between the toes, on the foot pad, or on the nailbed, causing swelling of the area and sometimes loss of the toenail.
This type of tumor often develops a secondary infection that can initially misdirect the diagnosis. Lameness is often the first noticeable symptom; swelling with bleeding or discharge from the affected area may also occur, and dogs may lick or chew the area.
Like the oral form of the disease, the digital is extremely aggressive with a dismal metastatic rate of 80%.
Cutaneous Melanoma
This is common in dogs and accounts for about 5 to 7% of all canine skin tumors. These tumors can form anywhere on the skin, and while most are malignant in humans, the majority are benign in dogs.
Benign skin melanomas are usually solitary, small, well-defined, deeply pigmented, firm, and move freely over underlying structures. The malignant form varies considerably in appearance, regardless of the location, and is usually asymmetrical. The color is variable, ranging from gray or brown to black, red, or even dark blue; they may have areas of pigmentation intermingled with areas of no pigment.
Malignant cutaneous melanomas are found most frequently on the head, ventral abdomen, and scrotum. The tumors tend to be fast-growing, and are often ulcerated and have developed a secondary infection. They are typically detected at a late stage with metastasis often detectable in regional lymph nodes. Cutaneous melanomas occurring on a mucocutaneous junction (a region of the body where the mucous membranes transitions to skin) have a higher potential to be aggressive and should be considered for treatment as a malignant form.
Ocular Melanoma
Melanoma can occur in and around a dog’s eyes. It can affect the eyelids, conjunctiva (the mucous membrane that covers the front of the eye and lines the inside of the eyelids), orbit (eye socket/eyeball), limbus (border of the cornea and the sclera), and uvea (the middle layer of the eye). Each location may exhibit different biological behaviors.
The good news is that these are frequently benign and rarely metastasize. That said, they can cause discomfort and problems as they grow, including vision impairment and blindness.
Malignancy tends to occur in the melanomas that form on the conjunctiva and in some of those that form on the eyelid and uveal. Additionally, malignant melanoma existing elsewhere in the body has the potential to metastasize to the eye. In general, ocular melanomas are less aggressive than the oral form; within the ocular melanoma group, the uveal form is characterized as being the most aggressive.
Symptoms of ocular melanoma can include a dark-colored mass in the eye or eyelid, darkening of the iris, irritation and redness of the eye, tearing, cloudy eyes, swelling in or around the eye, and twitching of the muscles around the eye.
Treatment
The first goal of melanoma treatment is to establish local and regional control, which is closely followed by the pursuit of systemic control.
Surgery
This is the primary and most common treatment option for all types of melanoma, including benign tumors. Complete surgical excision of the tumor, surrounding tissue, and any affected bone is required in an effort to obtain clean margins and effective local control. Dogs who have their tumors completely removed with surgery have the lowest chance of experiencing tumor regrowth during their lifetime. Not only can the surgical option occur promptly, it has increased curative intent and tends to be less expensive when compared to other modalities. The extent of the surgery will depend on the anatomic site and size of the melanoma.
Cutaneous melanomas usually require removal by lumpectomy/surgery, while other locations require a more aggressive excision.
Removal of a digital tumor often includes the amputation of the affected toe (with removal of all three phalanges to ensure adequate margins). Surgery to remove melanomas on the larger weight-bearing paw pads can be challenging, as there is the potential for loss of leg function; sometimes amputation of the limb may be the best course of action.
With ocular melanoma, the recommended treatment is enucleation (surgical removal of the eye) when tumors are confined inside the eye.
Oral melanomas may require partial removal of the maxilla or mandible (jaw) bones. While this sounds drastic, dogs tend to do very well after this type of surgery and experience little to no impact on function or quality of life. Cosmetic outcomes tend to be acceptable; if needed, reconstructive surgery can be performed to rebuild these areas.
Other melanoma sites within the oral cavity, such as sublingual or hard palate tumors, are prohibitive for complete surgical removal. Debulking surgeries can, however, reduce the amount of tumor present, but with incomplete surgical removal, oral melanomas tend to regrow quickly (often within days or weeks); subsequently, additional therapy protocols should be considered.
Recently, veterinary specialists have started advocating for removal of the regional lymph nodes and application of radiation therapy to the tumor site if tumor removal is incomplete or the disease has been found to have infiltrated the nodes. It is theorized that this change in protocol might account for the improved survival times occurring in nonvaccinated cases (see “Oncept: A Melanoma Vaccine,” on page 20).
Radiation Therapy
Melanomas were previously considered resistant to radiation therapy (RT), but many more recent studies are finding that there is a significant role for RT in achieving satisfactory local primary tumor control. In particular, RT is an effective treatment for malignant melanomas that cannot be surgically removed due to size or location, or as an adjunct treatment for tumors that either were not, or could not, be completely removed, and/or for cases where the disease has metastasized to local lymph nodes without distant metastasis.
Melanomas tend to respond best to hypofractionated/coarse fraction (radiation given less frequently but in larger doses) RT, typically administered once a week for four weeks and requiring anesthesia. In addition to the tumor site, RT will usually also be administered to the local lymph nodes if metastatic disease has been confirmed.
Side effects from RT tend be uncommon but may include sloughing of nails and foot pad surfaces and mild irritation of the mucous membranes of the mouth. If they do occur, they usually heal within one to two weeks and have minimal impact.
Tumors treated with RT can shrink significantly and may even become undetectable; accordingly, they can remain stable for a period of time. Compared to melanomas treated with surgical removal, however, those treated with RT alone have an increased incidence of recurrence. About 25 to 31% of dogs with oral malignant melanoma that is treated with RT respond partially and 51 to 69% respond completely.
Chemotherapy
Used alone, chemotherapy has not shown to be of much benefit for local control. Because options for treating canine malignant melanoma are fairly limited, chemotherapy has traditionally been used in an attempt to achieve systemic control in combination with surgery and/or radiation therapy.
The drugs typically used in the standard chemotherapy protocols include carboplatin, cisplatin, dacarbazine, melphalan, and doxorubicin.
Unfortunately, there are an increasing number of studies that are demonstrating that chemotherapy as an adjunct treatment does not have a significant impact on either time to progression or overall survival, even when compared to local treatment alone. There is extensive literature on the human counterpart of this approach that suggests melanoma is extremely resistant to chemotherapy. However, chemotherapy has been the most effective treatment available for delaying metastasis until the recent release of the melanoma vaccine (see “A Melanoma Vaccine,” below). At this time, it is still considered a viable but limited treatment option for dogs who don’t respond to the vaccine.
Targeted Chemotherapy
Although not a chemotherapy drug in the traditional sense, Palladia (toceranib) is a novel FDA-approved anticancer drug developed specifically for dogs. While it is labeled for use in dogs diagnosed with mast cell tumors, it has been evaluated for use against other forms of cancer.
Whereas traditional chemotherapy destroys all rapidly dividing cells, Palladia, a tyrosine kinase inhibitor, is a targeted therapy that inhibits specific receptors on the surface of cancer cells and nearby blood vessels (cutting off blood supply) that may result in delaying tumor growth and the progression of the disease. Palladia may be considered in cases that have become unresponsive to vaccine immunotherapy or standard chemotherapy protocols.
Anecdotal reports present varying responses to the drug, ranging from dogs having stable to partial responses for several months to others having no notable response.
[post-sticky note-id=’396310′]
Prognostic Factors
Malignant melanoma is one of the few cancers in dogs for which anatomic location is an extremely important prognostic indicator. Dogs diagnosed with Stage I melanomas have significantly longer survival times than dogs diagnosed with Stage II-IV disease, regardless of treatment chosen.
Negative prognostic factors that affect all types of malignant melanomas include metastasis and size of the tumor.
Oral Melanoma
Size of primary tumor is prognostic for metastasis and survival time (the smaller the tumor, the better).
A mitotic index less than or equal to 3 is associated with a better prognosis.
In general, the closer the tumor is to the front of the mouth, the better the prognosis.
The median survival time (MST) for untreated dogs is 65 days.
Survival times following surgery have been estimated at 17 to 18 months for Stage 1; 5 to 6 months for Stage II; 3 months for Stage III, and 1 month for Stage IV.
Survival time following removal of mandible is 9 to 11 months. In about 22% of the cases, the cancer will recur.
Survival time following removal of maxilla is about 4.5 to 10 months; about 48% of the cases will recur.
Response to radiation therapy is about 80%, with survival times of 211 to 363 days.
Digital Melanoma
The median survival time for dogs without lymph node involvement or metastasis and treated with surgical amputation of the digit is 12 months, with 42 to 57% surviving one year and 11 to 13% surviving two years.
Digital melanomas not located on the nail bed and having a low mitotic index are often cured with surgery alone.
Cutaneous Melanoma
Most cutaneous melanomas are benign, in which case the prognosis is excellent.
About 65% of dogs with cutaneous malignancy succumb within two years due to local recurrence or metastasis.
Dogs with malignant tumors that are less than 4 cm have a significantly better median survival time (12 months) than tumors greater than or equal to 4 cm (4 months). About 46% of dogs with the malignant tumors that are smaller than 4 cm will survive for at least two years.
Dogs with well-differentiated malignant tumors and a mitotic index less than or equal to 2 have an MST of 104 weeks.
Dogs with poorly differentiated malignant tumors and a mitotic index greater than or equal to 3 have an MST of 30 weeks.
Ocular Melanoma
The majority of ocular melanomas are benign, with an excellent prognosis.
Uveal is the most common malignant form, characterized by aggressive behavior.
Only 4 to 8% of malignant uveal melanomas metastasize to lungs and liver.
Malignant tumors removed by enucleation have a low incidence of reoccurrence.
Stay Vigilant for the Signs of Canine Melanoma
While there are other forms of skin cancer that develop in dogs, melanoma is the most common. If you find any raised lumps or bumps with or without coloration on your dog, consult your veterinarian as soon as possible.
I just did that very thing. My three-year-old mixed breed dog Tico has allergies, requiring frequent baths. I take that time to check him thoroughly – and this time I found a growth on the pad of his paw. We have an appointment next week with a veterinary specialist in internal medicine and oncology. I may be paranoid but after writing this, the fifth article in a series for WDJ on the most common canine cancers, I have earned a little overreaction.
The good news is that canine malignant melanoma is proving to be uniquely responsive to immune-based therapies, and there is evidence that the immune system could modulate the progression and metastasis of the disease. See “On the Horizon: Melanoma Treatments in Development,” on page 22 for more information.
The author’s 10-year-old
Cattle Dog-mix, Charlotte, walking on an underwater
treadmill, not long after a veterinarian predicted she’d never walk again. She’s made a nearly
full recovery from a
herniated spinal disc.
Almost immediately after my youngest dog, Sirius, had surgery on both of her knees last year, I brought her to see a physical therapist. This certified animal rehabilitation specialist created a personalized conditioning and rehabilitation plan for Sirius. One of the most useful modalities of treatment that Sirius received was hydrotherapy. It allowed her to maintain all the muscle she had developed in her Rally Obedience and agility training prior to her knee injury – and best yet, she loved the underwater treadmill. Sirius had one physical therapy session per week for eight weeks and was cleared to resume normal activity just 10 weeks post-surgery.
About 10 months later, my 10-year-old Cattle Dog-mix, Charlotte, went from walking multiple miles a day and training in sports to not being able to get up – overnight! We carried her into an emergency vet clinic where she was diagnosed with a herniated disc. We were told she would never walk comfortably again and that we should be thinking about of end-of-life decisions.
Two days later we brought her to the same veterinary rehabilitation specialist who worked with Sirius; we doubted the dire prognosis we had been given for Charlotte and weren’t ready to give up on a dog who had been so vigorous so recently! Through a combination of therapeutic treatment modalities, which included twice weekly hydrotherapy for the first month, Charlotte also made an (almost) complete recovery and was cleared to do everything she loves: hiking, swimming, long walks, trick training, etc.
I credit so much of my dogs’ recovery to hydrotherapy and skilled certified veterinary rehabilitation specialists.
HOW HYDROTHERAPY HELPS
Canine hydrotherapy is a beneficial treatment modality for dogs recovering from many orthopedic injuries, as well as degenerative conditions like arthritis, because allows dogs to move while bearing little or no weight on an injured limb. A less commonly considered benefit of the treatment is increased self-confidence for a dog who is injured or old.
Hydrotherapy isn’t dogs just splashing around in a pool, and the healing potential for injured dogs can’t be achieved by just bringing your dog somewhere for a recreational swim. There are two primary modalities of hydrotherapy treatment that dogs might receive: working on an underwater treadmill and therapeutic swimming. “The added resistance from water is excellent for increasing cardiovascular fitness, while providing low impact resistance muscle training,” says Marti Drum, DVM, Ph.D.
Dr. Drum is a Diplomate of the American College of Veterinary Sports Medicine and Rehabilitation (ACVSMR), a Certified Canine Rehabilitation Practitioner, and a Clinical Associate Professor in the Small Animal Clinical Sciences Department at the University of Tennessee, Knoxville. She is also the acting service chief of the physical rehabilitation service at the University of Tennessee Certificate Program for Canine Rehabilitation – and a huge fan of hydrotherapy!
[post-sticky note-id=’396304′]
UNDERWATER TREADMILL
The underwater treadmill used by veterinary specialists looks a lot like a fish tank. During treatment, your dog will enter the treadmill (sometimes with a life vest on) either on her own or with a certified technician. The dog enters the glass tank when it’s empty, and then the door is closed and the tank is slowly filled with warm water (between 80° and 94° F).
The depth of the tank is adjusted according to the dog’s size, her specific injury, and how far along she is in the recovery process. If the therapist determines that she should be bearing no weight whatsoever, the tank is filled to a level that enables the dog to float with her paws just barely touching the treadmill. The lower the water level, the more weight she will bear on her limbs.
Once the water reaches the desired depth the treadmill floor begins moving at the speed determined by the specialist. When this happens, most dogs naturally will begin walking – even dogs who are experiencing too much pain or are too weak to walk on land often begin moving in the underwater treadmill because of the support and buoyancy the water provides. Depending on where the individual dog is in her recovery process, jets may be used to add increasing levels of resistance and the speed of the treadmill can be adjusted to support building muscle or to maintain muscle.
In addition, says Dr. Drum, “The treadmill belt itself helps encourage a rhythmic gait to facilitate gait retraining.” This was certainly the case with my Charlotte, who had to be carried into the clinic, but a few days later, was able to walk comfortably in the underwater treadmill.
While walking on the underwater treadmill and walking on land are both low-impact forms of exercise, practitioners see stronger results for dogs who are able to exercise in underwater treadmills. The added resistance from the water helps dogs gain more muscle tone than from walking on land.
The water also supports a dog whose balance has been impaired. The support provided by the water enables and encourages dogs to move their joints in a nearly normal full range of motion. Plus, dogs who need to lose weight can burn more calories by working on an underwater treadmill than they can on land.
THERAPEUTIC SWIMMING
The second modality of canine hydrotherapy is therapeutic swimming, where dogs are gently guided into a small, heated pool and supported in swimming by a certified canine rehabilitation specialist. They are generally fitted with a canine life jacket, and dogs who are prone to ear infections may also be fitted with a canine “swim cap” that prevents water from entering their ears.
While beneficial to many dogs, therapeutic swimming isn’t an appropriate treatment for every injury. When swimming, most dogs primarily propel themselves through the water by using their front legs, so it wouldn’t usually be appropriate for dogs who have shoulder or front limb injuries, Dr. Drum says, as it can aggravate those conditions and slow recovery. Hydrotherapy may not be appropriate for dogs with groin injuries (strains of the iliopsoas muscle), either.
BENEFITS
Dogs with back, hip, and knee injuries often benefit from hydrotherapy, as do dogs who are recovering from surgical repair of injuries. And hydrotherapy is increasingly recommended as a useful treatment modality for proactively conditioning for canine athletes and working dogs.
But dogs don’t need to have an injury to benefit from hydrotherapy. Dr. Drum says osteoarthritis is the most common condition she sees treated with hydrotherapy. Older dogs who have arthritis constitute about half of the hydrotherapy patients that Dr. Drum sees, and she describes the benefits to these dogs as “profoundly positive.” Senior dogs who suffer from arthritis pain often experience decreased energy and activity, which can result in loss of muscle mass and weight gain – which, in turn, increases the stress on the already compromised joints.
Dr. Drum says, “It is not uncommon that our senior and geriatric patients experience a rejuvenation simply from starting a good hydrotherapy routine,” no more than once or twice a week, but at least once every two weeks. “You have to ‘use it or lose it’ to maintain muscle and cardiovascular fitness,” she says.
When my active, well-conditioned dog Charlotte was recovering from a herniated disc, she was unable to walk on land and quickly grew depressed and even more anxious than she is ordinarily. But during her hydrotherapy sessions, her confidence and happiness visibly increased as she discovered that she could move in the water without pain, and this seemed to give her more confidence as she slowly regained the ability to walk and move on land as well.
[post-sticky note-id=’396306′]
TREATMENT PLANS
Hydrotherapy will likely be only part of the treatment your dog receives. Dogs who are recovering from injury or surgery are likely to need multiple modalities of treatment in order to achieve optimal recovery. Hydrotherapy treatments are often provided in conjunction with structured exercises both at therapy sessions and for owners to follow-up with at home between sessions.
Anti-inflammatory and/or pain medications are usually prescribed, at least initially. Other holistic treatment modalities such as acupuncture and laser therapy may also be offered and provided by your dog’s rehabilitation specialist.
CERTIFICATIONS
If you think that your dog might benefit from hydrotherapy treatment, you can either ask your general-practice veterinarian for a referral, or schedule a consultation and evaluation with a certified veterinary rehabilitation specialist on your own. If you find a practitioner on your own, however, be aware that not all people who are offering these services have the same amount or type of training.
It’s increasingly easy to find dog trainers, massage therapists, and even veerinary practices who offer “canine conditioning” classes or workshops that include swimming in a therapy pool. If your dog simply needs help with weight loss, zero-impact exercise, or conditioning, these services may be just fine.
But if your dog is recovering from an injury or surgery, her therapy would be best guided by a professional with as much education and hands-on training and experience as you can find. It’s important to utilize hydrotherapy for an injured dog only under the supervision of specialized veterinary professionals who can determine whether the therapy is right for your dog, and to create an individualized treatment plan for your dog’s specific health needs.
If they are not certified specialists, the therapy they provide for your dog may be at best ineffective and at worst cause more injuries or prolong healing. As just one example, a common mistake for those not properly trained is to leave a dog on the treadmill for too long, which can result in the dog becoming sore and prolonging healing.
For injured or post-surgical dogs, look for certified rehabilitation practitioners – people who have completed specialized training on top of their DVM or veterinary nursing degrees. Dr. Drum advises that owners look for specialists with one of the following credentials:
Certified Canine Rehabilitation Practitioner (CCRP). (Dr. Drum especially likes the program at the University of Tennessee that offers this certification.)
Certified Canine Rehabilitation Therapist (CCRT). (Dr. Drum favors the University of Florida’s program for this certificate.)
Certified Canine Rehabilitation Assistant (CCRA) or Certified Canine Rehabilitation Veterinary Nurse. People with this certification can provide services under the supervision and guidance of a rehabilitation-certified veterinarian.
DUE DILIGENCE
Because hydrotherapy is such specialized treatment, there aren’t certified practitioners in every community and you may have to travel to find appropriate treatment for your dog.
Finally, no matter what services you are seeking for your dog, always ask for (and check) a practitioner’s references, and read any online reviews left by former clients.
I have never owned a dog with separation anxiety, thank goodness. The condition is hard on the dog who suffers from the condition and hard on the dog’s caretakers, too, including owners, vets, groomers, pet sitters, and dog walkers. Care must be taken to prevent triggering the dog’s panic at being left alone—in severe cases, even just long enough for the person caring for the dog to use the restroom!
