Chronic kidney disease (CKD) is one of the most common diseases in cats. Although more research is needed as to which early interventions have the greatest impact, there is plenty of scientific evidence that dietary changes can significantly reduce stress on failing kidneys and increase life expectancy. So, what do vets recommend when it comes to making diet choices for a cat with CKD?
Best food for cats with kidney disease (recommended top 3)
1. Royal Canin Renal
2. Hill’s k/d
3. Eukanuba Veterinary Diet Renal
Here’s a selection of the best CKD foods that come highly recommended:
For treats we recommend going with some that are low on sodium and contain lots of omega-3 fatty acids.
Managing CKD symptoms through diet changes
As chronic kidney disease progresses through the various stages, different complications arise that often require a tailored diet.
These are some of the most important dietary changes recommended to help a cat cope with the various symptoms assosciated with CKD:
- Change from dry to wet food to help increase liquid intake.
- Lower phosphorus to increase appetite,
- Lower calcium to improve the digestion,
- Higher potassium for maintaining a healty amount of muscle mass.
- Lower sodium to help combat high blood pressure
One of the kidneys’ main functions is to conserve water in the body. In CKD the kidneys gradually become less effective, so their ability to conserve water also decreases. A major symptom as a result of renal issues is dehydration and increased thirst. Maintaining a sufficient intake of fluids becomes very important to help support the kidneys in getting rid of waste materials in the blood.
Dehydration can be managed in several ways. The first line of defense should be to apply some of the standard strategies for getting a cat to drink more water. Canned wet foods are a major way of increasing fluid intake, since they normally contain around 75% water. These canned foods also tend to be more palatable, which helps because nausea and inappetence are also symptoms of CKD.
In more advanced CKD cases, more severe measures may be necessary. These can include intermittent intravenous fluid therapy and intermittent sub-cutaneous fluid therapy which are often given in a clinic.
Around 60% of cats with CKD have hyperphosphatemia (high phosphate levels in the blood). Since hyperphosphatemia is associated with a faster rate of disease progression, a diet low on phosphorous is especially important in these cases and studies have suggested the beneficial effects of such a diet can be quite dramatic. This can be achieved in one of two ways: through a phosphorous-restricted diet, or by administration of intestinal phosphate binders by mouth.
Most foods for CKD are designed to have low phosphate content. If blood phosphate concentrations remain high despite being on such a diet, further treatment with drugs known as ‘phosphate binders’ to reduce the amount of phosphate absorbed from the intestine may also be indicated. Examples of such binders are lanthanum and calcium acetate.
Some owners find binders (or any medication by mouth!) stressful to administer. Furthermore, when you add anything to a cat’s food, you risk creating a food aversion. There are palatable options available, but this tends to be down to individual kitty preference. Kidney diets are typically phosphorous restricted anyway, in which case oral binders can be reserved for when phosphate increases despite a kidney diet.
The symptoms of CKD are largely caused by uremia, a medical term for the accumulation of toxic products in the bloodstream as a result of protein breakdown. These toxins are normally filtered and excreted by the kidneys, but in CKD the kidneys are no longer able to keep up.
A restricted protein diet can therefore reduce the symptoms associated with CKD, and improve your cat’s quality of life. Since many meat-based proteins have a high phosphorous content, decreasing protein intake also helps to reduce the total amount of phosphorous in the body. This is a balancing act however! Too little protein can exacerbate the muscle wastage, weight loss and poor body condition seen with CKD.
Veterinary renal diets are specially formulated to have a reduced- but good quality- protein content, supporting the maintenance of muscle mass. Hills make two prescription diets: k/d Early Stage and k/d (for more advanced disease). The protein content differs to take into account the differing needs early in the disease process, compared with later on.
Protein restriction has to be performed with care, as too little protein can be extremely detrimental to the health of your cat.
Sodium & blood pressure
Cats with CKD are at a higher risk of developing hypertension. High blood pressure has a whole range of damaging effects throughout the body, and certainly doesn’t make it easier for the body to deal with a failing set of kidneys.
A mildly restricted sodium (salt) content in the diet can help manage high blood pressure. Most CKD foods are therefor low in salts.
When blood pressure is too high to manage through the diet, a group of drugs known as vasodilators can be administered to widen the arteries and lower the blood pressure. Another drug called amlodipine is also very effective.
Potassium excretion can increase in CKD. Hypokalemia (low blood potassium levels) is common in cats with CKD; it can be very dangerous and worsen kidney damage. Other possible side effects are muscle weakness and inappetence. While some kidney diets provide higher potassium levels when compared with regular diets, this really needs to be tailored to each individual cat’s needs.
Potassium levels are measures by analysis of a blood sample. When low potassium is identified, a specific potassium supplement would then be given, which are available in various forums like tablets, gels and powders that can be added to the meals. An example of a supplement that is given orally is VetPlus Kaminox.
Omega-3 Fatty Acids
Omega-3 fatty acids have a protective effect on the kidneys; by helping to maintain blood flow through the kidneys and by reducing inflammation.
Soluble fiber can help maintain a healthy bacterial population in the colon, which increases elimination of nitrogenous (protein break down) waste via the feces. It also helps to prevent constipation, which is common in cats with CKD.
Antioxidants are often added to renal diets to help protect the kidneys against more damage.
Acid can build up in the body in CKD, so added bicarbonate (or another alkalinizing agent) can help to counteract this.
Due to protein restriction, renal diets need to be calorie dense with moderate fat levels. This is to help maintain body weight and to improve palatability.
Recommended CKD foods
The following is a selection of foods designed to help reduce stress on the kidneys and increase your cat’s quality of life. Remember to always seek advice from your veterinarian before starting your cat on any veterinary specialist diet!
- Royal Canin Renal
Royal Canin make two stages of renal food- Early Renal and Renal. Each stage is uniquely balanced for the needs of cats in this stage of renal failure. They also make a Multipack with several flavors of food- perfect for cats with nausea.
- Hill’s k/d
Hills also make two kidney diets- k/d and Early k/d. This allows you to optimize your cat’s nutrition for the stage of kidney disease they’re in. Like Royal Canin, they also make a Starter Kit so you can find the right flavor and texture for your fussy feline.
- Eukanuba Veterinary Diet Renal
Eukanuba make this renal diet that satisfies most of the needs of a CKD cat. It contains extra Omega-3 fatty acids and a “nitrogen trap system” that aims to encourage spare nitrogen to be excreted in the feces rather than being passed to the kidneys.
Other diets for kidney disease
Royal Canin Renal Liquid- a complete diet for cats, bringing all their vitamins, minerals, and nutritional needs- but as a liquid. Useful for extreme cases, syringe feeding, or for cats with very low appetite.