Every day, thousands of dogs are diagnosed with kidney disease. The first suggestion most conventional veterinarians make is to switch from whatever the dog has been eating to a low-protein “kidney diet” food. Clients are sent home with bags or cans of “prescription” food and warned not to feed high-protein foods or treats of any kind.

Most dogs, even chow hounds, approach their new, low-protein food with suspicion, since these diets are generally much less palatable than foods that contain more animal protein. Many refuse to eat. Conventional veterinarians are used to this response and tell their clients to stick to the new food for their dogs’ own good. “Your old food is too high in protein and will actually speed kidney failure,” they warn. “Keep giving him the prescription food. He’ll come around when he gets hungry enough.”

Eventually most CRF patients do accept their new food, though without much gusto or enthusiasm. Worse, despite their food’s low protein levels, the dogs’ slow deterioration continues.

After their dogs have died, many owners look back and wonder whether they did the right thing. Now a new approach to feeding dogs with kidney disease offers a different scenario – one that’s more likely to keep CRF dogs, and their human companions, happy.

A paradigm shift

It’s a fact of life that not all medical discoveries and “breakthroughs” in disease treatment prove to be as promising as they seemed at first. Adopted on the basis of a few small, encouraging studies, some strategies are found later to cause mixed or even adverse results.

This is definitely the case with the currently predominant treatment strategy of giving dogs with CRF a low-protein diet. Newer research has radically changed and fine-tuned the dietary recommendations for canine CRF patients. Those using the latest recommendations to feed their CRF dogs a therapeutic home-prepared diet report excellent results. Best of all, most dogs love the combination of high-quality protein and freshly prepared ingredients.

About CRF

Chronic renal failure affects male and female dogs of all breeds and all ages. Its underlying cause may be hereditary or related to inflammation, tick disease, progressive degeneration, damage following acute renal failure, or unknown causes. Acute renal failure may be triggered by a trauma injury, exposure to poisons like antifreeze or rat poison, or damage caused by medications, bacterial infections (such as leptospirosis), fungal infections, or dehydration.

Many animals born with poorly constructed or poorly functioning kidneys succumb to kidney failure at a young age. Most cases of chronic renal failure are seen in dogs age seven or older. Chronic nephritis, a common diagnosis in CRF patients, involves low-grade, long-term inflammation of kidney tissue that causes permanent damage to delicate renal tissue.

The protein debate

As soon as they diagnose kidney disease, most American veterinarians prescribe a low-protein diet. They believe that protein harms the kidneys and that reducing protein consumption slows the progress of kidney degeneration. This is because early research on rats was assumed to be true for dogs, and excess protein causes problems for rats. A number of pet food manufacturers sell low-protein prescription diets for dogs with chronic renal failure, and those who prepare their own food at home are warned against feeding meat, poultry, and other foods that are high in protein.

“Those recommendations are based on a myth,” says Wendy Volhard, author of Holistic Guide for a Healthy Dog. “In fact, the whole theory of low-protein diets for dogs with kidney disease was blown apart in 1975 by David Kronfeld, PhD, who was at the time a veterinary researcher at the University of Pennsylvania. His concept was not to feed less protein but rather to feed higher-quality protein.

“The low-protein myth is like an old-wive’s tale, something based on ignorance that just won’t die. Yes, inferior-quality protein can harm a dog’s kidneys, but the solution isn’t to continue with inferior-quality ingredients and feed less of them. The solution is to improve the quality of ingredients and in that way provide what the dog needs for good health.”

Studies disproving the prevalent low-protein prescription have been widely published in veterinary journals and textbooks. But it is moving into the mainstream very slowly.

“Most vets who did not graduate from college in the last few years (and some of those as well) are still unaware of or dismiss the newer studies that show low-protein diets neither slow the progression of kidney disease nor prolong life,” says Mary Straus, a lifetime dog lover from the San Francisco Bay area who researches health and nutrition issues.

“Too many dogs are forced to eat Prescription Diet k/d® or similar low-protein prescription foods,” says Straus. “These can actually cause harm. When protein levels are very low, the body will cannibalize itself to get the protein it needs. This creates more waste products than if you feed the proper amount of high-quality protein in the first place. Also, k/d is not very palatable, and many dogs with kidney disease will eat only enough of it to survive, or stop eating entirely if that is all they are offered.”

Older dogs actually require a higher level of protein to maintain their body stores of protein than do younger adult dogs, says veterinary nutritionist Patricia Schenck, DVM, PhD, of Michigan State University’s Center for Veterinary Medicine. In an article published in Veterinary Nutritionist, Dr. Schenck wrote, “Reducing dietary protein in older pets may have adverse effects. As pets age, their ability to utilize nutrients decreases. The only time dietary protein restriction is appropriate in renal failure is when the disease has become severe.”

Healthy geriatric dogs require about 50 percent more protein than young adults, say canine health writers Susan Thorpe-Vargas, PhD, and John C. Cargill, MA. Depending on the quality of the protein, they say, it should make up 20 to 30 percent of total calories ingested. “Protein restriction can result in impaired wound healing, diminished immune function, and lowered enzyme activities and cellular turnover. Dogs with impaired renal function do better with dietary phosphorus restrictions.”

A new action plan

Mary Straus’s dog Nattie was a healthy, athletic Chinese Shar-Pei who had no trouble keeping up with young dogs even at 10 and 11 years of age. She ate kibble and received annual vaccinations until 1997, when Straus learned about the health benefits of raw diets and the harm that can be caused by repeated vaccinations. Nattie was 10 years old when she was converted to a raw diet and stopped receiving vaccinations. Four years later, at age 14, Nattie was diagnosed with kidney disease. After much research, Straus put the newest diet plan into place for Nattie.

“I modified her diet to reduce its phosphorus but kept her protein levels high,” says Straus. “Her diet was around 37 percent protein on a dry matter basis, and she thrived. Her kidney numbers actually improved for two years, and when she died at age 16, her illness had nothing to do with kidney disease.

“People need to know this information, as well as how to formulate a homemade diet or what foods to add if they are going to feed k/d or one of the other low-protein commercial diets for kidney disease.”

Dietary goals

When developing a diet for dogs with kidney failure, the recommendations from leading experts are to feed:

• Moderate to high amounts of fat
• Moderate amounts of high-quality protein
• Low amounts of phosphorus
• Moderate amounts of low-phosphorus carbohydrates
• Plenty of water, juices, broth, and other liquids

Although guidelines vary, a sensible goal is a diet whose total calories come 1/3 from fat, 1/3 from protein, and 1/3 from carbohydrates.

Fat provides calories and energy, and most dogs have an easy time digesting it. Good sources of saturated fat include fatty meats, butter, whole-milk yogurt, egg yolks, and coconut oil.

Polyunsaturated vegetable oils, such as canola, corn, soy, safflower, sunflower, and flax seed oil, are not recommended for CRF patients. Neither is cod liver oil, because of its high vitamin D content, which failing kidneys have difficulty processing. But fish oil (fish body oil, not fish liver oil) has been shown to help dogs with CRF.

When adding fats and oils to the home-prepared diet, start with small amounts and increase quantities gradually. Too much too soon can lead to diarrhea. Dogs prone to pancreatitis should be carefully monitored.

What are the best sources of protein? Most experts consider eggs to contain the highest-quality protein, but their yolks contain moderate amounts of phosphorous. One strategy for feeding eggs to CRF dogs is to feed one or two egg whites for every whole egg. Calcium is a phosphorus binder, so add small amounts of finely ground eggshell to each meal (½ teaspoon per pound of food) to help reduce the amount of phosphorus absorbed by the body.

Other foods high in phosphorous include bones, fish with bones, cheese, and organ meats. “Bones are so high in phosphorus,” says Straus. “that I would avoid them or feed them in small amounts, such as one-third the normal quantity, even with early stage CRF. Like egg yolks, organ meats such as kidney and liver contain many nutrients that are important for canine health and should be included, but in moderate amounts.”

Further diet tips

Recently, green tripe, a food traditionally fed in Europe, has become a staple for many American dogs, including CRF patients. Green tripe is the raw, unprocessed stomachs of cud-chewing animals like cows, goats, or sheep. Supermarket tripe is white because it has been bleached and deodorized, which destroys fragile nutrients. Green tripe contains easily digestible protein, beneficial bacteria, abundant enzymes, and relatively low phosphorus levels.

Tripe smells awful to humans but sublime to dogs, including CRF patients who have otherwise lost interest in food. Thanks to increasing demand, frozen green tripe is available from mail order sources and some local distributors of raw frozen foods.

If you choose to feed a prescription dry or canned food rather than a home-prepared diet, add fresh protein foods, either raw or cooked, such as meat, eggs, egg whites, and tripe, especially in the early stages of the disease.

If you feed a diet based on raw meaty bones, substantially reduce the amount of bone. If the diet calls for bone meal, like the Natural Diet developed by Wendy Volhard, follow her advice to switch from lean to fatty meats and substitute calcium carbonate for the bone meal to reduce phosphorus levels.

While dogs are not designed to consume grains or starchy vegetables, most CRF diets include up to 50 percent carbohydrates in order to provide calories and nutrients while keeping phosphorus levels low. Steaming or boiling vegetables reduces phosphorus levels if you discard the cooking water. Alternatively, puree or juice them to improve assimilation. Note, however, that dogs with arthritis may be sensitive to nightshade plants, which include white potatoes, peppers, eggplant, and tomatoes.

Whole wheat, oatmeal, brown rice, millet, and other whole grains are moderately high in phosphorus and should not be fed often or in large amounts. White rice is low in phosphorus, and glutinous or sticky rice is the lowest-phosphorus grain. To help make grains more digestible (as described in “It’s All in How You Make It,” WDJ March 2001), soak them overnight to remove enzyme-suppressors and naturally occurring toxins.

“I have had good luck with Malt-o-Meal, which is low in phosphorus,” says Straus. “You have to be careful about feeding vegetables to dogs with kidney disease. I recommend using white potatoes and yams because they provide a lot of calories without adding much phosphorus, unlike many of the low-cal veggies.”

Dogs with high blood pressure, which can be related to kidney disease, may need reduced salt in their food. Home-prepared diets are naturally low in salt, but cottage cheese is high in salt, canned fish can be rinsed to remove salt, and processed foods should be checked for their sodium content.

Because dehydration creates serious problems for dogs with kidney disease, it’s important to provide abundant water. “Make sure fresh water is always available,” suggests Straus, “even if excess drinking causes your dog to become incontinent. If your dog already drinks a lot of water, ask your vet about giving subcutaneous fluids to help the dog stay hydrated.” Hard water contains minerals that are best avoided, so use filtered or low-mineral bottled water.

Dogs with kidney disease can lose interest in food, so look for foods and flavors that can revitalize a flagging appetite. “It’s important for these dogs to eat something,” says Straus, “even if it’s not one of the recommended foods. Try offering your dog’s food at different temperatures, experiment with raw versus cooked, and offer multiple small meals rather than just one or two large ones. My Nattie wouldn’t eat raw eggs, but she loved eggs scrambled with a bit of cheese. The cheese wasn’t the best thing for her, but it got her to eat.”

Green tripe can be added to food as a flavor enhancer, as can Seacure, a very fishy-smelling powder sold as a protein supplement. “If you feed a commercial food like k/d and your dog won’t eat it, find something else, preferably a homemade diet that provides high-quality protein while controlling the amount of phosphorus,” she says.

Plus, she adds, most dogs love fresh food. “The higher moisture levels in fresh foods help protect their kidneys, and they feel better and enjoy life more.”

Also With This Article Click here to view “Can Meat Cause Kidney Failure”

Click here to view “Chronic Kidney Disease in Dogs”

by Randy Kidd, DVM, PhD Put simply, the function of the kidneys is to make urine, a “waste” product of body metabolism. Of course, there is much more to the kidneys. They are powerful chemical factories that: • Remove waste products, toxins, and drugs from the body • Balance the body’s fluids and help maintain a constant body pH • Release hormones that regulate blood pressure and control the production of red blood cells • Produce an activated form of vitamin D that promotes strong, healthy bones Anatomy and physiology The two kidneys lie against the back abdominal wall, lateral to the spine, in the lumbar region. They are encapsulated organs, shaped somewhat like a kidney bean, and their size varies with the size of the dog. The functional unit of the kidney is the nephron. There are perhaps a million nephrons in each kidney, each one comprised of a glomerulus and a long tubule that eventually empties into the ureter.

The glomerulus is a congregation of blood vessels contained within Bowman’s capsule, and the glomeruli are located in the outer portion of each kidney (cortex). Blood is filtered as it passes through the kidney’s collection of glomeruli. After filtration in the glomeruli, the resulting protein-free fluid is passed into a thin tubule. The proximal tubule descends into the med-ulla of the kidney and then makes a sharp U-turn (at the loop of Henle) to return into the cortex, where it empties into a collecting duct, even-tually exiting via the ureter. The tubules are responsible for secretion of some substances (such as drugs and their by-products, uric acid, fatty acids, and bile salts) and reabsorption of a variety of other permeable solutes, among them glucose, amino acids, vitamins, minerals, urea, and some salts, notably sodium, chloride, and potassium. Urine passes into the bladder where it’s stored until it’s excreted via the urethra. Blood pressure is controlled by a complex interplay of hormones. In response to decreased blood pressure (as a consequence of chronic congestive heart failure or CHF, for example) the kidneys release renin. This is a proteolytic enzyme that acts on liver-produced angiotensinogen, which is converted to angiotensin I and then to angiotensin II. Angiotensin II causes retention of sodium and water, in part through stimulation of the synthesis and release of aldosterone by the adrenal cortex. Angiotensin II also causes vasoconstriction, thus increasing vascular resistance. Vasoconstriction and water retention place further stress on the already compromised heart muscles, and ultimately these conditions may also damage the kidney’s nephrons. Thus, angiotensin-converting enzyme (ACE) inhibitors are widely used in treating CHF in dogs, and many practitioners include them for the treatment of kidney disease. The maintenance of the body’s overall acid/base balance also relies on a complex mechanism that depends on adequate respiratory and digestive function as well as kidney mechanisms. The kidney’s role in keeping the body’s pH within a healthy range is related to balancing the potassium and hydrogen ion retention and depletion and is especially important during hypoxia (when the animal is not receiving enough oxygen, either from poor respiratory function and/or a diminished supply of red blood cells). The kidney is both the sensor organ and the major site for the production of erythropoietin, the hormone that regulates production of red blood cells. Chronic renal failure is thus typically accompanied with a mild to moderate anemia. Bone health is reliant upon healthy kidneys in at least two ways. First, vitamin D is necessary for the utilization of calcium, and the activated form of vitamin D is produced in the kidney. Second, normal kidneys excrete phosphorous; chronic renal failure may lead to excessive retention of phosphorous, which in turn causes an imbalance between calcium and phosphorous. Vitamin D must be metabolically activated (via hydroxylation in the liver and kidney) before it can function physiologically; the conversion in the kidneys is the rate-limiting step in vitamin D metabolism. Occasionally the imbalance of calcium to phosphorous seen with increased retention of phosphorous may create a decreased amount of circulating calcium. Parathyroid gland hyperplasia occurs (to maintain serum calcium in normal ranges), and the resultant high parathyroid hormone (PTH) concentrations result in increased bone resorption, which ultimately creates thinning of the bone. Note here that the major contributor to the softening of the bones is an imbalance between calcium and phosphorous levels in the body. Rarely, the opposite of the above condition (hypercalcemia) occurs with renal disease, but the pathogenesis of this condition is unknown. Note also that calcium metabolism is involved with bladder and kidney stone formation, which often makes for complicated therapeutic decisions whenever we need to treat kidney disease. Notes about renal disease Renal disease refers to the presence of morphologic or functional lesions in one or both kidneys, regardless of extent. Renal failure refers to the retention of nitrogenous waste products of protein metabolism, regardless of the cause. Renal insufficiency is a term that has been used to describe a state of reduced renal function that has not yet resulted in retention of nitrogenous waste products. Azotemia (from the Greek azote, meaning “nitrogen”) is defined as an excess of urea or other nitrogenous compounds in the blood. You may also hear the term “uremia” used to replace azotemia, but uremia has now come to refer to the entire constellation of signs and symptoms of chronic renal failure: nausea, vomiting, anorexia, uremic odor of breath, pruritus (itchy skin), neuromuscular disorders, pain and twitching of muscles, hypertension, edema, mental confusion, and acid-base and electrolyte imbalances. Typical causes of azotemia are classified by their location: prerenal, from diminished blood flow into the kidneys; post-renal, usually due to a blockage of the “outflow vessels” (ureters or urethra); and renal disease that can be caused by a lack of proper function of any of the components of the nephron (the glomerulus or tubules), or it can be caused by conditions affecting the tissues between nephrons. Finally, to help determine treatment, practitioners also like to know if the disease is acute or chronic, and if it appears to be progressive or nonprogressive. Diagnosis of urinary disease Noticeable symptoms and signs of urinary system disease will, of course, vary with the disease and its severity, but the following general symptoms should make you suspicious of urinary system disease. Dysuria, that is, any abnormality of urination, including polyuria (passage of large amounts of urine in a given period), may be the animal’s attempt to compensate for diminished functional capacity of the kidneys, and it is often associated with polydipsia or chronic excessive thirst. Hematuria indicates the presence of blood in the urine and may be due to renal calculi, trauma, or destruction of the red blood cells within the body (this latter condition is more correctly referred to as hemoglobinuria). Oliguria (from the Greek oligos, meaning little or few) describes the secretion of a diminished amount of urine in relation to the fluid intake, and stranguria (from the Greek stranx, meaning “drop”) describes slow and painful discharge of urine, due to spasms of the urethra and bladder. Anuria is defined as the complete suppression of urinary secretion by the kidneys. It is an emergency condition whenever urine flow has ceased, whether due to kidney shut down (shock, for example) or blockage of the outflow vessels of the urinary tract (stones). See your veterinarian immediately. If renal disease proceeds to chronic renal failure, uremia results, and (as mentioned above) uremia produces an entire constellation of signs and symptoms. Other symptoms, seemingly unrelated to the kidneys, may occur with chronic renal failure: pulmonary edema and coughing, bone conditions related to softening of the boney mass, heart conditions related to improper control of blood pressure, and symptoms related to anemia such as difficulty breathing, exercise intolerance, restlessness, etc. Symptoms, even those that become evident when specific diagnostic aids such as urinalysis and blood chemistries are employed, may not occur until a very high percentage of the nephrons are not functioning properly. Perhaps as many as 70 percent or more may need to be dysfunctional before specific symptoms are detected. Urinalysis The primary diagnostic aid for kidney disease, a typical urinalysis includes the urine’s specific gravity, its pH, and the presence of abnormal amounts of substances such as protein, glucose, and creatinine. Important findings in the urinary sediment include red or white blood cells, crystals, bacteria, or other organisms such as yeasts. A functional kidney is able to concentrate (or dilute) urine to a specific gravity that is different from that of the blood plasma (circulating blood plasma has a specific gravity of 1.010 + 2); kidney disease is diagnosed when the urine specific gravity remains at 1.010 + 2, regardless of the dog’s state of hydration. Normal pH of the carnivorous animal’s urine is acid (below pH of 7), and it typically becomes more basic with bacterial infections. The consistent presence of glucose in the urine (glucosuria) indicates the likelihood of diabetes mellitus. The presence of cells or microorganisms in the sediment are indicators of infection or inflammation. Moderate amounts of protein in the urine signify that there is a “leak” in the glomerular filtration system, that the kidneys are unable to retain proteins in the bloodstream. See “Urine Luck” (February 2004) for more information on urinalysis. Blood tests Blood chemistry tests can also help diagnose some urine system dysfunctions. Renal excretion of urea is accomplished by glomerular filtration. Urea is also reabsorbed passively in the renal tubules, which means that its blood levels will increase whenever there are slower tubular flow rates – during dehydration or blood volume depletion, for example. So, one important result of the blood chemistry test examines the blood urea nitrogen (BUN) levels. Creatinine, a product of the normal metabolism of muscles, is excreted by the kidneys by glomerular filtration. Non-renal variables, such as excessive muscular activity, muscle necrosis, and possibly ingestion of a meal of cooked meats, may have a small and transient effect on the blood creatinine level, but it is still considered a good indicator for glomerular function. Creatinine and BUN assays offer an indirect measurement of the glomerular filtration rate (GFR), which in turn is a good assessment for the overall functional capacity of the glomeruli. Phosphorous retention results from declining function of the glomerulus, and blood phosphorous levels may be extremely high with chronic renal disease. Blood albumin levels may also be low due to inadequate retention of proteins, and the decreased levels of protein may lead to edema and/or malnourishment. A mild anemia often occurs with severe kidney disease (due to improper production of erythropoietin). Elevated white cell counts may point to infections in the urinary tract. A complete blood count (CBC) can help detect these conditions. Other diagnostic tests include abdominal X-rays, contrast studies of the urinary tract, ultrasonic exams of the kidneys and bladder, and renal biopsy. Some diseases (diabetes and CHF in particular) may predispose the dog to renal failure, so tests to rule these out may be needed. See “Passing the Blood Test” (November 2003) for more information on blood chemistry analysis. Prerenal conditions These conditions result from reduced blood flow to the kidneys due to such causes as dehydration, congestive heart failure, or shock. They usually resolve completely with appropriate treatment, but they may also progress to renal disease and renal failure. Renal conditions

Every practitioner will tell you that kidney disease is one of the most common entities seen in vet practices daily. Acute renal failure usually occurs following a major insult to the kidneys. Potential causes include vascular conditions (such as disseminated intravascular coagulation or DIC), immune mediated conditions (such as lupus), renal infections, and ingestion of toxins (such as heavy metals, aminoglycoside antibiotics, painkillers, and ethylene glycol or antifreeze). Once the instigating factor(s) is removed with specific therapy, and supportive therapy is instituted (for example, fluids to enhance flow through the nephrons), the kidney typically returns to its normal function. If the disease process is allowed to proceed for a few days to a few weeks, chronic renal disease may ensue. Chronic renal failure (CRF) presents a far more complex and ever-evolving picture. Therapy often must be adapted to the individual case and its progress over time. Basic principles of therapy include: • Determination of the cause of the disease, if at all possible. • Removal of potential toxins – including drugs that are known to be harmful to the kidneys. • Restoration of blood flow through the glomeruli. Fluids, given sub-Q, IV, or orally if possible, can be life-saving. Some dogs with CRF can manage a fairly good quality of life so long as fluids are administered on a routine basis – daily or several times a week. • Dietary changes to help bring the body and the urinary system back into balance (see nutrition, below). • Specific treatments to help counter the cause of the disease. Infections, for example, can be treated with antibiotics, herbs, acupuncture, or immune system-enhancing methods. Primary glomerulopathies are uncommon in dogs. They are often due to an immune-mediated disease that ultimately creates the formation of immune complexes in the glomerular capillary wall. These immune complexes prevent normal glomerular functioning, and the dog is unable to retain protein. The primary symptoms are frequently due to the protein loss: weight loss, edema or ascites, dyspnea (difficulty breathing, due to pleural effusions or pulmonary edema), coagulation disorders, and proteinuria. Severe cases can result in renal failure and uremia. Drugs are a prevalent cause of renal disease, and there are many that have been implicated. Aminoglycoside antibiotics are the second most common cause of acute renal disease in dogs (behind only antifreeze toxicity), and the frequency of toxicities seems to be increasing every year. Although their spectrum of toxic severity varies, all antibiotics in the aminoglycoside classification are nephrotoxic. Aminoglycoside antibiotics include neomycin, kanamycin, gentamicin, amikacin, and streptomycin. Many painkillers (including nonsteroidal anti-inflammatory drugs or NSAIDs), chemotherapy agents, and many other drugs have been reported to be nephrotoxic. Some herbs have also been cited as potentially nephrotoxic, including wormwood (Artemisia absinthium); sassafras (Sassafras albidium); horse chestnut (Aesculus hippocastanum); chaparral (Larrea spp.); and periwinkle (Vinca minor). Bottom line: Ask about the potential renal toxicities for any drug or therapy your practitioner recommends. Postrenal conditions There are several potential causes of partial or complete obstruction of the outflow vessels of the urinary tract, including tumors, enlarged prostate in the male dog, trauma that causes blood clots or eventual scarring, and uroliths or stones. Of these, stones are the most common. Generalized symptoms of constriction of the urinary tract include nonproductive straining to urinate, increased frequency of urination (without an increased volume), and blood in the urine. Symptoms may be present for a period, followed by periods of apparently normal function. Uroliths (also known as urinary calculi or stones) are crystalline concretions, found in the urinary tract, that contain mostly inorganic crystalloids, along with a small amount of organic matrix. Almost any mineral substance that passes through the kidneys could form one of these precipitates, and under favorable conditions, a hardened concretion could develop. Stones are named according to the predominate crystal found within. The most common stones found in dogs are struvite and calcium oxalate. Typically, when a dog has uroliths, crystals are seen in urine sediment. Depending on the stone’s size and mineral composition, X-rays can be used for detection; however, some uroliths don’t show up well on X-ray films. Laboratory analysis of the stones is needed to positive identify the minerals they contain. Some breeds are predisposed to forming uroliths, and some breeds are especially prone to forming a specific type of urolith. For example, due to a genetic defect in uric acid metabolism, Dalmatians are predisposed to urate calculi formation. With each type of urolith, there are predisposing factors that tend to precipitate the problem, and each of these factors is specific for the type of urolith formed. For example, oxalate crystals form in acidic urine, struvite crystals tend to form in alkaline urine. Check with your vet for these specifics, to help formulate a plan for treatment and prevention. Symptoms vary with the location and the size of the urolith. They include frequent attempts to urinate, straining or inability to urinate, hematuria, overdistended bladder, or signs of uremia. Uroliths may also be totally or periodically asymptomatic. They often cause secondary irritation and result in infections. Struvite is composed of magnesium ammonium phosphate, in varying ratios and degrees of purity. Struvite uroliths form in alkaline, concentrated urine, and there is a genetic predisposition for their formation. Medical management may be helpful and may even dissolve the stones. A medical protocol would include enhancing urine flow (diuresis along with plenty of water intake), production of acidic urine, and dietary means to reduce magnesium and phosphorous and (perhaps) to reduce protein. (For more on protein, see nutrition section, below.) Calcium oxalate uroliths, in contrast, must be removed surgically, since attempts to dislodge them by nutritional means alone have not proven successful. An acute urinary obstruction is an emergency condition that requires immediate care. Urine backup creates a toxic level of urea in the body which may, within hours, cause neurological signs and eventually lead to death. Your veterinarian may need to use anesthesia to pass a catheter to dislodge the stone(s) for immediate relief. Other urinary tract diseases Infections of the urinary tract include cystitis (infection of the bladder), pyelonephritis (kidney infection), and urethral infections. Infections can be caused by a variety of microorganisms, and they are conventionally treated with antibiotics or alternatively with herbs or other methods. Clinical symptoms include the list of urinary dysfunctions: hematuria, difficulty and increased frequency of urination, etc. Infections are usually easily diagnosed by examining the urine sediment for the presence of bacteria and/or blood cells. Culture and sensitivity can also be performed to determine the antibiotic of choice; herbal remedies typically have a broad range of activity, although their potency may not be quite as strong. While symptoms of urinary infections or obstruction may wax and wane, depending on the degree of obstruction and/or the amount of irritation to the urinary tract, you can often predict an event by observing precursor symptoms such increased attempts to urinate (with poor results), straining to urinate, or blood-stained urine. At the onset of these symptoms, I’ve had excellent results with dandelion root (Taraxacum officinale) and Oregon grape root (Berberis aquifolium), perhaps along with echinacea (Echinacea spp.) to enhance the immune system. Of course, make sure the dog drinks plenty of water and continues to be able to urinate freely. Dandelion acts as a diuretic and Oregon grape root has antibiotic activity; the combination is often enough to ward off further development of disease while we try to correct the problem nutritionally or with other medications. There are two problems of the urinary tract – urinary incontinence and conditions of the prostate – that deserve more discussion, but since they are more related to the reproductive tract, I’ll cover them in the next installation of the Tour of the Dog. The urinary system is also affected with a long list of physical anomalies, many of which have a familial tendency. Included in this list are renal dysplasia and hypoplasia, renal agenesis, polycystic kidneys, renal cysts, and some of the glomerulopathies. Neoplastic diseases also occur along the length of the urinary tract, and their diagnosis and treatment are the same as for neoplasias affecting other sites. Western and other therapies Western medical therapies for treating urinary system diseases are aimed at the following: removing or discontinuing instigating factors (infections, for example, or nephrotoxic drugs); improving hydration so that urine flow through the tract is optimal; providing nutritional support that minimizes stress to the kidney while it helps return the body back to balance; and using specific medications that apply to the ongoing condition of the patient. Alternative medicines can be helpful for treating many of the common conditions that affect the urinary system. Alternative medicines may prove even more beneficial for maintaining a balance of the “extra” functions of the kidney – the functions that help the animal maintain homeostasis. “Alternative” or “holistic” practitioners will try to create the same benefits that their Western colleagues expect, typically by using a more natural approach – with home-prepared foods rather than commercial “prescription” diets, as one example. A holistic practitioner will also likely employ one of the alternative methods to try to re-establish homeostasis. Nutrition will likely be the mainstay for the holistic practitioner treating renal disease. Holistic treatments will vary according to individual patient needs and will likely change as the healing process progresses. Nutrition Nutritional approaches to treating urinary tract diseases are fairly common now, especially since the dog food companies have seen the potential for increased sales. It’s important to remember that each type of urinary tract disease requires an individualized nutritional approach. With this in mind, there are some basics that may help you when you devise a diet for your dog. It is important to maintain fluid flow through the kidney, so the dog’s diet should either be moist or should encourage drinking lots of water. Some diets include salt to enhance thirst, but salt encourages fluid retention, which is not good for the heart. Excess phosphorous may speed the progression of renal conditions. Low-phosphorus diets are difficult to formulate, so most commercial foods contain “phosphorous binders” – substances that contain ingredients that remove phos-phorous from the blood. Some diets or therapeutic regimes use potassium citrate, an alkalizing agent that helps maintain potassium levels in the body and helps with the management of calcium oxalate uroliths. Antioxidants (such as Omega-3 and -6 fatty acids) can speed the repair of renal damage from disease. Vitamins A, C, and E can be used for their antioxidant effects, but these vitamins can affect the pH of the dog’s urine. If your dog has a history of or predisposition to stones, work with your vet to monitor the pH of the dog’s urine when you feed these supplements. B vitamin supplements can be beneficial, especially if diuretics are used to enhance urine flow. One of the most controversial topics in canine nutrition has to do with proteins in the diet of kidney-compromised dogs. Studies have produced conflicting results. In years past, we thought that we helped compromised kidney function by providing a low-protein diet. Not all current research supports this, however. Recent studies indicate that a low-protein diet (less than about 10 percent) may actually be detrimental when treating kidney disease. What seems to be the consensus now is that a diet moderately high in protein (30 to 35 percent), provided in high quality, readily assimilated proteins, is most supportive for long-term care of the kidney-compromised dog. What none of the studies shows is what most interests a holistic practitioner: How much “vitality” is contained in the food. Processed foods have almost no healthy “energy.” Raw, home-prepared foods have the dietary vitality that dogs evolved with, foods that retain their natural capacity to provide overall health and vigor. I have no scientific data to support this, but my guess is that an unprocessed diet that approximates the high protein diet of the wild canine will ultimately prove to be the best one for preventing renal disease. (Editor’s note: WDJ will publish an article on diets for kidney-compromised dogs in a few months.) Herbal therapies The list of herbs that may be helpful for aiding urinary problems is extensive. For starters, many herbs are diuretic, with a range of activity varying from slight to profound. Most conditions of the urinary tract benefit from an increased flow of urine, so almost any herb will be helpful in this regard. Further herbal selection depends on the specific condition – for example, one herb that has been used to treat kidney stones is bearberry or uva-ursi (Arcto-staphylos uva-ursi). My favorite herbal combination for non-specific urinary tract conditions, especially the recurring types that may be related to low grade infections, are dandelion root and Oregon grape root. Go, team! As I consider the various and sundry functions of the urinary system and how to best keep all its aspects healthy and functioning and in accord with other body systems, I can’t help but think that this is a prime example where a team approach may be the most beneficial. To be most effective, we need the diagnostic acumen of Western medicine, the services of a good, holistic dietitian (to help us provide the best balance by using whole foods), and an herbalist who is well informed on potential kidney toxicities as well as the benefits of the herbs. Finally, to provide the most beneficial treatment for a specific kidney disease, there will be occasions when Western medicine is simply more prudent and better than any of the alternatives available. Also With This Article Click here to view “Can Meat Cause Kidney Failure?” Click here to view “A Low-Protein ‘Kidney Diet’ is Not Always The Answer” Click here to view “Chronic Kidney Disease in Dogs” -Dr. Randy Kidd earned his DVM degree from Ohio State University and his PhD in Pathology/Clinical Pathology from Kansas State University. A past president of the American Holistic Veterinary Medical Association, he’s author of Dr. Kidd’s Guide to Herbal Dog Care and Dr. Kidd’s Guide to Herbal Cat Care.