Healthy Low-Fat Diets For Dogs With Special Dietary Needs
Dogs with special dietary needs like pancreatitis or IBS can really benefit from a low-fat diet.
In previous issues we've talked about the causes, diagnosis, and treatment of pancreatitis. In this article we will discuss diets that can be used long term for dogs who cannot tolerate too much fat in their diet. These guidelines are meant for adult maintenance only, not for puppies or females who are pregnant or nursing, as their requirements are different.
Many dogs with chronic pancreatitis and those prone to recurrent attacks of acute pancreatitis do better when fed diets that are low in fat. Dogs with exocrine pancreatic insufficiency (EPI) due to damage to the pancreas, or with inflammatory bowel disease (IBD), may also respond favorably to a low-fat diet. Some dogs need a low-fat diet to control hyperlipidemia (high levels of triglycerides in the blood) that can lead to pancreatitis.
Dogs with fat intolerance or mal-absorption may show signs such as diarrhea and weight loss, or steatorrhea (excessive excretion of fat in the stool, resulting in large, pale, greasy, and malodorous stools) in more severe cases. Fat malabsorption can also be associated with liver and gall bladder disease, intestinal infection (viral, bacterial, or parasites), lymphangiectasia, and other conditions. It’s a good idea to try a low-fat diet for any dog with digestive problems to see if he improves, though if no improvement is seen, it need not be continued.
How Much Fat is OK for dogs?
As a rule, veterinarians consider a diet with less than 10 percent fat on a dry matter basis (less than 17 percent of calories from fat) to be low fat, while diets with 10 to 15 percent fat (17 to 23 percent of calories) are considered to contain a moderate amount of fat. Foods with more than 20 percent fat are considered high-fat. A few dogs may need a very low-fat diet, especially if they have hyperlipidemia, or if they react to foods with higher levels of fat.
When comparing the percentage of fat in different foods, you must consider the food’s moisture content. The percentage of fat in wet food (canned or fresh) must be converted to dry matter (DM) for comparison, or to use the guidelines above. To do the conversion, first determine the amount of dry matter by subtracting the percentage of moisture from 100, then divide the percentage of fat by the result. For example, if a food is 75 percent moisture and 5 percent fat, divide 5 by 25 (100 - 75) to get 20 percent fat DM.
Percentages give you only a rough estimate of the actual amount of fat your dog will consume.
For a more exact figure, calculate the grams of fat per 1,000 kcal (kilocalories, the standard caloric measurement). For simplicity’s sake, I will call this GFK, though that is not a standard abbreviation. Veterinary nutritionists consider diets to be low-fat if they have less than 25 GFK (22.5 percent of calories from fat). This measurement can be used for any type of food: dry, canned, or fresh.
The ratio of fat to calories is more accurate than the percentage of fat in the diet, since the amount of food your dog needs to consume is determined by calories.
For example, a diet that is 10 percent fat with 4,000 kcal/kg provides 25 GFK, while a diet that is 8 percent fat with 2,700 kcal/kg provides 30 GFK.
In other words, for every 1,000 kcal your dog consumes, he would get 30 grams of fat from the food with 8 percent fat, but only 25 grams of fat from the food with 10 percent fat. See the sidebars on the following pages for instructions on how to easily calculate the GFK in various foods and combinations.
Here is a list of the percentages of fat that would translate to 25 grams per 1,000 kcal for foods with various calories:
2.5 percent fat @ 1,000 kcal/kg
5 percent fat @ 2,000 kcal/kg
7.5 percent fat @ 3,000 kcal/kg
10 percent fat @ 4,000 kcal/kg
Vegetarian diets are sometimes recommended to provide a low-fat diet. I do not advise feeding your dog a vegetarian diet, whether commercial or homemade. See “Have Dinner In,” (WDJ, April 2007) for more information on how such a diet can lead to serious nutritional deficiencies.
Some low-fat recipes for dogs are excessively low in fat, providing as little as 5 to 8 GFK, with as much as seven times more starches than meat. With very few exceptions, it’s not necessary to feed such an extremely low-fat diet to dogs recovering from or prone to pancreatitis or with other forms of fat intolerance, nor is such a diet likely to be nutritionally adequate, regardless of how many supplements you add. The NRC (National Research Council) recommends a minimum of 11.1 GFK for adult dogs (10 percent of calories from fat, or around 5 percent fat DM).
Diets that are too low in fat can lead to deficiencies of fat-soluble vitamins and problems with the skin and coat; they can also leave your dog feeling tired and hungry all the time. It’s important to feed adequate fat unless your dog absolutely cannot tolerate it. In that case, you can add easily digestible fat in the form of medium-chain triglycerides (MCTs), found in coconut oil and MCT oil (generally made from coconut and/or palm kernel oil). See last month’s article for more information on MCTs.
Not all dogs who have had acute pancreatitis, or who have EPI, need a low-fat diet. Many dogs who have experienced acute pancreatitis can return to a normal diet with no problem. A recent study showed that severe fat restriction (less than 13 percent of calories from fat, or less than 15 GFK) failed to show any significant benefit for dogs with EPI.
A case report of three German Shepherd Dogs with EPI demonstrated that a diet with 19 percent fat (on a dry matter basis) was well tolerated and resulted in weight gain, decreased diarrhea, and an improved coat (the diet used hydrolyzed protein, which is processed in such a way as to render the proteins nearly hypoallergenic). Diets with 43 percent calories from fat have been shown to promote better protein, fat, and carbohydrate digestibility compared to diets containing 18 and 27 percent calories from fat in dogs with experimental EPI.
Low-Fat Commercial Diets
In order to calculate the amount of fat in commercial foods, you will need to know the kcal/kg. If this information is not provided on the label of the product you’re interested in, call or e-mail the company. Ask them to provide the actual amount of fat from a nutritional analysis if possible, rather than the guaranteed minimum amount that is shown on the label. (See “Find the Amount of Fat in Commercial Foods.” You’ll see that the actual amount of fat in a food may be much higher than the “minimum” amount shown on the label.)
Most senior and light diets are relatively low in fat, but look for those that are not also low in protein. Low-protein diets should be avoided, as they can increase the risk of both hyperlipidemia and pancreatitis. Diets that are low in both protein and fat are mostly carbohydrates. Dogs get more nutritional value from protein than from carbohydrates, so it’s better to feed a diet that is higher in protein and therefore lower in carbohydrates. You can increase the amount of protein in the diet by adding high-protein, low-fat fresh foods, if needed. Moderate amounts of protein (up to 30 percent on a dry matter basis, or 23 percent of calories) are recommended for dogs recovering from acute pancreatitis.
Low-fat foods are inherently less palatable (not as tasty). If your dog is unwilling to eat low-fat foods, try adding some low- or moderate-fat canned or fresh foods, or low-sodium nonfat broth, to make the food more attractive. See the homemade diet section below for more information on foods to add. You can also combine low-fat food with moderate-fat food to keep fat at reasonable levels while increasing palatability.
Veterinarians debate about the amount of fiber that is best for dogs recovering from pancreatitis. Some dogs respond better to low-fiber diets (0.5 to 5 percent DM), using mixed soluble and insoluble fiber types, while others do better on diets that include moderate levels of insoluble fiber (10 to 15 percent). The difference may depend on what other gastrointestinal disorders the dog has. Low fiber is recommended for dogs in the initial recovery stages of acute pancreatitis, as fiber slows gastric emptying, which may prolong pancreatic stimulation.
Low-Fat Homemade Diets
To make a low-fat homemade diet, feed about half carbohydrates, and half low-fat meat, eggs, and dairy. The percentage of carbs can be decreased, and the amount of meat increased, if you use very low-fat cuts, or boil them to remove most of the fat.
The majority of the carbohydrates should be starchy foods, such as rice, oatmeal, barley, quinoa, pasta, potatoes, sweet potatoes, pumpkin, and winter squashes (e.g., acorn and butternut), to supply low-fat calories. Other types of vegetables, such as broccoli, summer squash, and leafy greens can be included, but they supply fewer calories so they can’t replace the starchy carbs. You can also use a low-fat pre-mix designed to balance out a homemade diet, such as Preference from The Honest Kitchen.
The other half of the diet should be mostly low-fat meats, or meats cooked to remove much of their fat. Skinless chicken breast is very low in fat, but other parts can be used as long as you remove the skin and visible fat. Turkey, venison, goat, buffalo, and rabbit are low in fat, while lamb and pork are generally high in fat. Ground beef comes in varying levels of fat.
Whole eggs are relatively high in fat but are highly nutritious, so they should be included in the diet in limited amounts. A large egg has about 5 grams of fat, which is not a lot for a very large dog, but too much for smaller dogs. You can hard boil eggs and then feed just a portion each day, or split them between multiple dogs. Almost all of the fat and calories are in the yolks, so the whites alone can be added to increase protein without increasing fat, if needed. When feeding just egg whites, they should either be cooked or a B vitamin supplement should be added, as raw egg whites can deplete biotin over time when fed without the yolks.
Low-fat or nonfat dairy products are also good to include in the diet. Cottage cheese, plain yogurt, and kefir (a cultured milk product that is easy to make at home using low-fat or nonfat milk) are all good choices. Avoid other cheeses; even low-fat ones are high in fat (nonfat is okay).
Homemade diets should include organ meat, and most organs are low in fat. Liver and kidney should be fed in small amounts only, no more than 5 to 10 percent of the total diet (around 1 to 1.5 ounces organ meat per pound of food). Beef heart is quite low in fat and is nutritionally more of a muscle meat, so it can be fed in larger quantities, as long as your dog does well with it.
Fruits such as apple, banana, melon, papaya, and blueberries are fine to include in the diet in small amounts. Avoid avocados, which are high in fat.
Meat can be fed either raw or cooked. Certain types of cooking, such as boiling and skimming off the fat, can be used to reduce the amount of fat, while other types, such as frying in oil, will increase the amount of fat. You can buy less expensive, fattier cuts of meat if you remove the fat by cooking or trimming before feeding. Grains and starchy carbs should be cooked to improve their digestibility, while other vegetables must be either cooked or pureed in a food processor, juicer, or blender in order to be digestible by dogs (raw whole veggies are not harmful, but provide little nutritional value).
If you feed raw meaty bones, the amounts should be small, as these tend to be high in fat. Be sure to remove the skin and visible fat from poultry, and avoid fattier cuts such as lamb and pork necks and breast (riblets).
This is one case where “balance over time” does not apply. A high-fat meal can’t be balanced out later with a low-fat meal. Instead, combine foods so that no meals are high in fat. Some dogs prone to digestive problems do better with more fiber, while others do better with less. Many vegetables and fruits are high in fiber, as are beans and some grains, while white rice has little fiber. If you need to add fiber, you can use canned pumpkin or psyllium.
Balancing a Homemade Diet
You will need to add calcium to your homemade diet, unless you feed at least 20 percent raw meaty bones (RMBs, where the bone is consumed) or use a pre-mix designed to balance out a homemade diet.
Because you need to feed more food when feeding a low-fat diet in order to supply the same number of calories, it’s better to calculate the amount of calcium needed based on the calories your dog consumes rather than the weight of the food. The National Research Council recommends 1 gram (1,000 mg) of calcium per 1,000 kcal for adult dogs. Another way to compute the amount of calcium your dog needs is by body weight: the NRC recommends 30 mg calcium per pound of body weight (65 mg/kg) daily. Be sure to divide this daily amount by the number of meals you feed.
If you are feeding RMBs but they are less than 20 percent of the diet, adjust the amount of calcium proportionately. For example, if your diet is 10 percent RMBs, you would need to add only half as much calcium as the NRC recommends to balance out the rest of the diet.
You should also adjust the calcium amount if you feed part commercial and part homemade. There’s no need to add calcium if the homemade food is just a small percentage of the diet, say 25 percent or less, but if you feed more than that, calculate the amount of calcium based on the percentage of the diet that is made up of homemade food. For example, if you feed half commercial and half homemade, give half as much calcium as your dog would need based on body weight, or calculate the calories in the homemade portion and base the amount of calcium to add on that amount alone. You can use any form of calcium, such as calcium carbonate or calcium citrate. You can also use bone meal. Ground eggshells can be used to supply calcium. Rinse and dry the eggshells, then grind them in a clean coffee grinder or blender. One-half of a teaspoon of ground eggshell provides approximately 1,000 mg of elemental calcium.
Dietary Supplements for Dogs
If the diet you feed lacks variety, especially organ meats, it’s best to add a supplement designed to balance out a homemade diet. Two supplements are designed to balance out high-carb diets: Balance IT Canine and Furoshnikov’s Formulas Vitamins & Minerals for Home-Cooked Dog Food.
When using Balance IT, calculate the amount of calcium your dog should have based on the formulas above, then figure how many scoops of the supplement are needed to supply that amount of calcium.
See Spot Live Longer Homemade Dinner Mixes can also be used, but give a little less than the recommended amount, since it’s made for diets that are higher in fat. Each of these supplements supplies calcium in the proper amounts, so there’s no need to add more.
Even if the diet you’re feeding has a lot of variety, it’s a good idea to add certain supplements. As discussed last month, digestive enzymes and probiotics may help to control the effects of chronic pancreatitis, and sometimes are helpful for other digestive problems. Fish body oil, such as salmon oil (not cod liver oil), and antioxidants, including vitamins C and E, beta carotene, and selenium, may help reduce the risk of acute pancreatitis. Dogs with chronic pancreatitis can be deficient in B vitamins, so a B-complex supplement is also recommended.
Diet versus Single Recipe
Many people feel more confident feeding a diet that has been designed by a veterinary nutritionist, but these can have limitations. Most nutritionists provide the dog owner with a single recipe rather than a diet, and in fact caution against making any substitutions to the recipe in order to keep each meal “complete and balanced.”
The problem with this approach is that variety is key to good nutrition. Human nutritionists would never supply a single recipe and expect clients to eat that and only that for the rest of their lives. Instead, they give guidelines for which foods can be eaten in quantity, which in moderation, and which should be avoided or eaten in only very limited amounts. That’s what I’ve tried to do here. If you do use a recipe from a nutritionist long term, don’t be afraid to sometimes substitute other foods in the same category as those used in the recipe if they have similar amounts of fat (as long as your dog does not have severe digestive problems or food allergies that require a very limited diet).
The other problem with these recipes is that often they are excessively high in carbohydrates, with minimal amounts of protein, and rely on supplements to provide many nutrients. Carbohydrates are needed to supply low-fat calories for dogs who require a low-fat diet, but they provide less nutritional value than animal products such as meat, eggs, and dairy. Diets that are high in carbohydrates must rely on synthetic supplements to supply much of the nutrition that your dog needs.
A diet that contains more animal products and variety will meet more of your dog’s nutritional needs naturally, without requiring a complete vitamin-mineral supplement. Also, diets that rely on supplements may lack nutrients as yet unidentified as necessary or beneficial, as was the case with taurine before it was discovered that a deficiency leads to heart disease in cats (and some dog breeds as well). Taurine is one example of a nutrient that is found in meat, but not plant products.
If your dog cannot handle much fat in his diet, then you’ll also need to use low-fat treats. Carrot, apple, and banana pieces or green beans can be used, if your dog likes them. Many people buy or make dried sweet potato slices for dogs prone to pancreatitis. Rice cakes are another option.
Many commercial treats are low in fat. Check the fat percentage on the label of dry treats to get an idea of how much fat they contain; most dry treats with 8 percent or less of fat should be fine. Moist treats are harder to calculate, since you must either convert the fat percentage to dry matter, or know the number of calories so that you can use one of the formulas above in order to determine the actual amount of fat (most treat labels do not provide information about calories).
Some dehydrated or freeze-dried lung and other meats are low in fat. Avoid using dehydrated chicken jerky, though, as most are imported from China (check the small print carefully), and the AVMA and FDA have warned that these treats have been linked to kidney failure in dogs, though no cause has yet been found. Also avoid using pieces of cheese, hot dogs, lunch meats (even those marked low fat), and other fatty foods as treats.
You can create your own dehydrated treats by drying thin slices of low-fat meat in a dehydrator or an oven set to a very low temperature. Sprinkle with garlic powder or nonfat Parmesan cheese before drying to make them even more enticing. Anise is another flavor that dogs really like. Try boiling beef heart in water with a couple of teaspoons of anise seed powder, then cut into small pieces to use as treats.
Use low-fat or nonfat yogurt in place of peanut butter or cheese for stuffing Kongs. Put them in the freezer to create a frozen yogurt treat that will last a long time.
Some chews, such as bully sticks (also called pizzles), are low in fat, while others, such as dried trachea and pig ears, are quite a bit higher. Dried tendons appear to be low in fat, but may be greasy, so use your own judgment. Similar products from different manufacturers may vary in fat content, so pay attention both to the amount of fat listed on the label and to the feel of the chew. Marrow bones are filled with fat and should be avoided. Knuckle bones also appear to be too high in fat to use safely.
Two low-fat chews that last a long time are Himalayan dog chews, which are made from yak and cow milk and are less than one percent fat, and deer antlers, such as those marketed by Lucky Buck. Mindy Fenton, who owns K9 Raw Diet, carries these and other low-fat chews, and has helped many customers whose dogs are prone to pancreatitis to find chews that work for them.
I found several anecdotal reports of rawhide chews, particularly those that were imported, causing acute pancreatitis in dogs, but could find no studies or warnings from veterinarians or other reliable sources on this topic. Some people fear that the act of chewing for long periods may overstimulate the pancreas and cause problems for some dogs, but I could find no supporting evidence. A veterinary pancreatitis specialist confirmed that he feels chewing is not a problem as long as the chews are not high in fat (such as pig ears). Keep an eye on your dog and discontinue giving chews if they appear to cause any discomfort.
Do What Works
Remember that the bottom line is always to do what works for your dog. Numbers tell you only so much, and nutritional analyses for both commercial and fresh foods may vary from what you’re actually feeding.
If your dog continues to have problems, try different foods to see if he tolerates some better than others. If possible, feed frequent small meals, which are easier to digest. Experiment with supplements to find those that seem to help your dog. Keep a journal of what you feed, including treats and supplements, to help you see patterns and identify ingredients that might cause problems for your dog.
If digestive disorders continue no matter what you feed, work with your vet to look for other causes, such as intestinal infection, parasites, or food allergies that may be an underlying factor.
Mary Straus does research on canine health and nutrition topics as an avocation. She is the owner of the DogAware.com website. She lives near San Francisco with her almost 17-year-old dog, Piglet.