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The complete diet for cats with urinary problems

For past 5 decades urinary problems such as FUS (Feline Urinary Syndrome) or FLUTD (Feline Lower Urinary Tract Disease) as well as kidney failure are reaching epidemic proportions in domestic population of cats. It is not mere coincidence the pathologhy of domestic cats urinary system has increased as soon as more people started feeding dry commercial diets.

A quick search of any pet food website regarding the moisture content of most dry cat foods will tell you that they are generally only 8 to 10% moisture. Cats fed a dry diet exclusively are at a significant water deficit compared to cats eating a natural diet. They are only consuming about 12 to 15% of their ideal daily water intake in their food. You may think that the cat can make it up by drinking more water, but cats innately have a low thirst drive, as they evolved to eat prey consisting of so much moisture.

Feline urine tends to be more concentrated than urine of other mammalian species. This is one reason that the urine of intact male cats has such a strong odor. The fact that cats produce such highly concentrated urine, especially when fed low moisture foods such as kibble, makes them more susceptible to urinary crystals and stones and to urinary bladder irritation, a contributing factor to Feline Lower Urinary Tract Disease or FLUTD. Basic chemistry tells us that the more concentrated a solution is, and in this case the solution is urine, the more likely any solutes are to precipitate out and form crystals and stones. The more concentrated the urine is, the more likely it is that it may irritate the delicate lining of the urinary bladder.


Cats with FUS or FLUTD can be permanently cured if switched to species appropriate diet as discussed on this page, in timely fashion.

An important component of the recommended treatment of FLUTD cats is the feeding of canned food or raw foods exclusively, which are about 70% moisture. This increases the cat's water intake, dilutes the urine and decreases the probability of crystals.² I also recommend supplementing with vitamin C in order to lower ph of cat's urine.

Recent research has suggested that higher protein in the diet may help to decrease the occurrence of struvite crystals and stones for two reasons. With increased protein, less magnesium is excreted in the urine, and the increased protein causes an osmotic diureses. Water is drawn into the kidneys and makes the cat urinate more.¹ Additionally, "Dry cat foods with their high plant content, cause a very alkaline urine pH…This unnaturally high concentration of minerals and other constituents in the urine along with alkaline pH, leads to UTI (Urinary Tract Inflammation).

For my patients, I certainly do not recommend the feeding of the special prescription diets that contain added synthetic substances to artificially control the pH of the urine. Treating urinary problems in this way may contribute to kidney disease, as recent evidence has suggested that the low magnesium content of these diets may have a detrimental effect on the kidneys over time.³



During the course of my practice I have witnessed too many cats perishing due to a kidney failure. What frustrates me the most is that this life threatening disease can be prevented with simple dietary adjustments.

Kidney AnatomyKidney AnatomyThe kidneys regulate the water and salt balance in the body, maintaining hydration, electrolyte levels and regulating blood pressure. As proteins are metabolized by the body for energy, by-products are produced and circulated in the blood. It's the kidney's job to remove these toxic substances. Waste products such as urea nitrogen, creatinine and phosphorus, as well as certain drug metabolites, are all filtered from the blood and excreted in the urine.

You may be familiar with the names of these by-products of protein breakdown if your cat has had blood work done. These are what are measured in the blood to detect declining kidney function – high levels mean that the kidneys aren't working normally. A complication is that the kidneys possess an amazing capacity for compensation. As much as 75% of kidney function must be lost before we can detect abnormally high blood values for these substances. Sometimes we see increased thirst and urination before the blood values rise above normal, as the kidneys become less able to conserve water, but not always. Since so much kidney function is lost by the time disease is usually detected, we need to do everything we can to help our cats maintain good kidney health in the first place.

You may have been told to feed your kidney-compromised cat a diet that has a reduced protein content. Should you do it? Recent research demonstrates that diets high in protein have no detrimental effect on the kidneys, and animals with mildly decreased kidney function do not benefit from reduced protein diets.

There is evidence that restricting protein may actually slow down the filtering action of the kidneys.

Rather than restricting protein that cats depend upon for their energy requirements, reducing phosphorus in the diet can help many cats with kidney disease. Phosphorous restriction is important in order to prevent the development of renal secondary hyperparathyroidism , a condition where excess phosphorous leads to an altered calcium/phosphorous balance. The end result of this imbalance causes calcium to be drawn from the cat's bones and deposited into the tissues and organs, including the kidneys, further impairing their function.

Recognising that raw meat diets are not high in protein is important. They are appropriate protein levels for an obligate carnivore. No studies have conclusively demonstrated that severe restriction of protein alone will prevent worsening of renal failure. All of the studies have restricted the protein and lowered the phosphorous levels and restricted salt. It is now thought that lowering of the serum phosphate concentration is much more important in management of renal failure in cats, due to their nature as obligate carnivores  and their high requirement for protein. The renal diets studied have also all been supplemented with potassium, B-vitamins and omega-3-fatty acids.

So, how do we achieve this with a raw diet? Interestingly enough, our standard raw meat diet is almost perfect for cats in renal failure. Highly digestible, good quality protein with lots of natural essential fatty acids from wild caught prey. High in B-vitamins due to the organs in the diet and low phosphate levels due to the raw meaty bones being naturally low in phosphates compared to a cereal based diet. If you are feeding farmed meats, then it may be a good idea to add some omega-3 supplements, as farmed meat is lower in this essential fatty acid.

A raw meat diet is ideal for any cat and fits the requirements of an obligate carnivore. If we consider the majority of cats are in a state of chronic dehydration due to dry commercial diets, it is not surprising that older cats have a tendency to renal failure. Getting these renal cats onto a high moisture content raw diet can be a real turning point for them.
More in depth information  on how to manage your cats with chronic kidney disease, as well as individually tailored diet plan can be obtained during the consultation.
Diagnosis and treatment of specific conditions should always be in consultation with your own veterinarian. Vetmalta.com disclaims all warranties and liability related to the veterinary advice and information provided on this site.


1. M. Hashimoto, M. Funaba, M. Abe and S. "Dietary Protein Levels Affect Water Intake and Urinary Excretion of Magnesium and Phosphorous in Laboratory Cats," Japanese Association for Laboratory Animal Science, Experimental Animals 44, no. 1, January 1995, 29-35.

2. Y. H. Cottam, P. Caley, S. Wamberg and W. H. Hendriks, "Feline Reference Values for Urine Composition," The American Society for Nutritional Sciences, The Journal of Nutrition, no. 132, June 2002, 1754S-1756S.

3. Michael W. Fox, Elizabeth Hodgkins and Marion E. Smart, Not Fit For a Dog: The Truth About Manufactured Dog and Cat Food, 2009, Quill Driver Books, 107.

4. D.R. Finco, S.A. Brown, C.A. Brown, W.A. Crowell, G. Sunvold and T.L. Cooper, "Protein and Calorie Effects on Progression of Induced Chronic Renal Failure in Cats," American Journal of Veterinary Research 59, no. 5, May 1998, 575-82.

5. Kenneth C. Bovée, DVM, MMedSc, "Mythology of Protein Restriction for Dogs with Reduced Renal Function," Supplement to Compendium on Continuing Education for the Practicing Veterinarian 21, no. 11, 1999, 15-20.

6. L.A. Ross, D.R. Finco and W.A. Crowell, "Effect of Dietary Phosphorus Restriction on the Kidneys of Cats with Reduced Renal Mass," American Journal of Veterinary Research 43, June 1982, no. 6, 1023-6.

7. SA Brown, VMD, PhD, M Rickertsen, BS, S Sheldon, DVM, "Effects of an Intestinal Phosphorus Binder on Serum Phosphorus and Parathyroid Hormone Concentration in Cats With Reduced Renal Function," International Journal of Applied Research in Veterinary Medicine Vol 6, No 3, 2008, 155-160.




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