Feline and Canine Kidney Disease

Feline and Canine Kidney Disease
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Kidneys are one of the most important organs in the body. If your pet has been diagnosed with kidney disease, you may be feeling a bit uneasy. Learn more about this disease here.

Itโ€™s easy to disregard the kidneys. In fact, you may assume that once youโ€™ve house trained your cat or dog you never have to think about them at all. The kidneys, though, have several very important functions including regulating minerals in the body, stimulating bone marrow to produce red blood cells, helping regulate blood pressure, and, of course, filtering and excreting waste. Because they play such a central role in the body, diseases that affect the kidneys can have a significant impact on your petโ€™s overall health. Thus, all pet owners should know the facts about kidney disease.

Causes of Kidney Disease in Dogs and Cats

Unfortunately, kidney disease is fairly common in dogs and cats. Bacterial infections of the kidneys can usually be successfully treated with antibiotics, but kidney failure (also known as renal failure) cannot be cured.

Cats and dogs may suffer acute kidney failure in which kidney functions begin to shut down quickly. Exposure to toxins or poisons, shock, dehydration, congestive heart failure, and other sudden events may cause acute renal failure. Pets usually require emergency treatment for this condition, but even with prompt attention the prognosis is usually poor.

The most common type of renal failure in pets is chronic. Itโ€™s often a disease of older dogs or cats. However, it can also occur in young pets as a result of long-standing infections, tumors, cysts, viral diseases, or other conditions that damage the parts of the kidneys that filter waste.

Symptoms of Kidney Disease in Dogs and Cats

If your pet seems to have pain around the kidneys and passes urine that contains pus or blood, most likely the problem is a bacterial infection. In cases of kidney failure (chronic or acute), the first symptoms are usually increased thirst and more frequent urination. By the time you see these problems, the damage is usually irreversible. With advanced renal failure, cats and dogs may suffer from a variety of symptoms, including eating or digestive problems (refusing to eat, vomiting, diarrhea); behavioral changes (lack of energy, depression); and physical signs (dry coat, discoloration of the tongue).

Treatment for Kidney Disease in Dogs and Cats

In the case of a bacterial infection in the kidneys, antibiotic treatments should offer a full cure.

With kidney failure, there is no cure. However, several treatment options can help extend the life of your cat or dog while trying to relieve symptoms, such as Benazepril. The first step is to provide plenty of water for your pet. Next, your veterinarian might recommend switching your pet to a low-protein diet in order to reduce the amount of waste the kidneys need to process. Other treatments that can relieve symptoms include: increasing your petโ€™s intake of water soluble vitamins and potassium, giving your pet sodium chloride tablets, trying to lower parathyroid hormone levels in your petโ€™s body with low doses of vitamin D, and (if necessary) offering medication to treat bladder stones. Some pet owners have sought out kidney dialysis and kidney transplants for their pets. However, these are very expensive treatment options and still include some risks.

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4 Principles of Nutrition for Treating Kidney Disease

Prescription Diets For Dogs With Kidney Disease 

Dogs with kidney disease require a special diet to slow the progression of the disease and to prevent other health problems associated with kidney disease. Because diseased kidneys must work much harder to filter out toxins, and this throws off their normal hormone balance, dogs can get high blood pressure, phosphorus buildup in the blood, and/or B-vitamin deficiency. Diet is an important component of treatment and a prescription diet, such as Hill's k/d, can keep the disease from getting worse and encourage the proper balance of vitamins and minerals.

Switching to a prescription kidney food should occur gradually over one to two weeks. And you should always follow the directions of your veterinarian. Vets usually recommend the best diet based on your dog's stage of kidney failure, but there are some common features of most kidney-friendly diet foods:

Lots of Water

Dogs with kidney disease need much more water because their kidneys are more active trying to eliminate toxins. Kidney diet foods may come in either a canned or dry version.

  • Canned food is preferred, because it has significantly higher moisture content
  • Especially when using dry food, it will be important to provide plenty of clean, fresh water for your dog. You can even soak your dog's dry food in water to encourage water intake.

Kidney Disease Diet Nutrients (Compared to Regular Food)



Less (kidney diets are 13-18% protein)

Reduces protein buildup


More (kidney diets are 16-20% fat)

Easier to digest than protein for energy


More (first ingredient)

Easier to digest than protein for energy



Slows disease progression



Reduces blood pressure

Omega 3 Fatty Acids


Reduces blood pressure and inflammation in kidneys

Vitamins and Extra Antioxidants


Controls cell damage and improves immune system


Reduced Protein

Protein in kidney disease diets is a matter of some controversy: reduced protein in advanced kidney disease can keep protein from building up, but when the disease is in its early stages, some protein can still be processed and it is an essential part of the diet. If protein is too high your dog can build up byproducts of protein that the kidney would usually filter out. Buildup of the metabolite called urea is problematic when very high. It's part of what makes a dog feel sick when suffering from kidney disease.

Prescription diets have decreased levels of protein, so you should work with your vet to determine the best food with the right amount of protein based on your dog's stage of illness. At all stages, it's very important to feed your dog high quality protein to rebuild unhealthy cells.

Increased Fat and Carbohydrates

Even with less protein, dogs will still need fat and carbohydrates for energy. Fat and carbohydrates are easier to digest, so you will see higher amounts in kidney disease foods than in regular dog food. Fat in the diet usually increases the palatability of the food too, making your dog keen to eat enough so they won't lose weight.

Reduced Phosphorus

When kidneys are less effective, they can allow phosphorus to build up in the blood. Phosphorous buildup can
lead to decreased kidney function and increased symptoms of kidney failure. Most phosphorus comes from protein and kidney diets usually have a reduced level of phosphorus to combat this buildup.

Reduced Sodium

When kidneys are struggling, some of the hormonal balance related to kidney blood pressure will be off. This leads to mild to modest hypertension, which can lead to high blood pressure. And too much sodium is not good for high blood pressure. Prescription foods have lower levels of sodium, but they are not sodium-free. Dogs still need sodium in their diets for healthy nervous system function and to prevent dehydration.

Increased Water-Soluble Vitamins and Other Antioxidants

Because dogs with kidney disease drink more water and eliminate more often, they also are eliminating important vitamins, like vitamins B and C. Luckily, prescription diets try to counter this with increased amounts of these commonly deficient vitamins. Antioxidants are also good for controlling cell damage and improving immune system health.

Omega-3 Fatty Acids

Long-chain omega-3 fatty acids, such as those found in fish oils, are also effective at reducing blood pressure and kidney inflammation. They can improve blood flow and improve general kidney health. While these should be included in prescription kidney food, they may not be present in high enough amounts, so your vet may recommend a supplement.

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This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.

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