Kidney insufficiency, also called kidney disease or renal disease, is a serious problem for pets, and will need immediate treatment. Dietary modification is the best way to treat kidney disease in cats and dogs and slow its progression.
It is well known among veterinarians that the following dietary principles will prolong your dog or cat’s life significantly, which is why your veterinarian will prescribe a therapeutic kidney diet when your pet is diagnosed with kidney disease.
Be aware that in general, food formulated for animals with kidney disease will have carbohydrates listed as the first ingredient. When it comes to healthy dogs and cats, this is something most guidance tells pet owners to avoid, yet for your pet with kidney disease, a different set of guidelines is needed.
The 4 Major Principles of Managing Kidney Disease
1. Protein Restriction:
Most people familiar with kidney disease hear that protein restriction is essential for treatment.
The truth is that while protein does not directly affect the progression of the disease, it does have other unwanted side effects.
When too much protein is present, the kidney cannot appropriately get rid of nitrogen, which is then turned into a product called urea. Your veterinarian may note that your dog or cat’s blood urea nitrogen (BUN) is high. This can be due to causes other than kidney problems, but it does indicate that your pet may have kidney disease.
When too much urea builds up in the body, it will make your dog or cat feel ill and nauseous. Protein is often restricted once urea starts to rise out of the normal range in order to keep this from happening.
Unfortunately over-the-counter dog and cat foods will not be appropriate since they supply levels of protein for a healthy adult dog or cat. For a dog with kidney disease, protein intake should be about 1/2 of what's in typical food. Cats with kidney disease should have about 1/4 to 1/3 the amount that's in typical food.
2. Phosphorus Restriction:
Though perhaps less well-known than protein restriction, phosphorus restriction is one of the more important concepts, since increased phosphorus is directly associated with the progression of kidney disease.
The most relevant indicator of kidney problems in your dog or cat’s blood work is creatinine concentrations in the blood. Creatinine is a normal byproduct of muscle function and is normally filtered out of the body by the kidney. If the body cannot do this efficiently, then the creatinine level in the blood increases above normal.
The same common ingredients in your pet’s diet are often sources of protein as well as phosphorus. So oftentimes, as creatinine starts to increase out of the normal range, urea eventually follows. Protein restriction goes hand-in-hand with phosphorus restriction.
3. Salt Restriction:
In many cases, as the kidney fails, blood pressure rises in the kidney blood vessels, making management of “kidney hypertension” a must.
The easiest way to help control kidney hypertension is to decrease the amount of salt your pet gets. Many over-the-counter foods contain about 2-8 times what’s appropriate, so kidney diets have been formulated to contain low salt content to combat the hypertension issue.
4. Increasing Long Chain Omega-Three Fatty Acids:
The long chain omega-three fatty acids from fish oils will help combat kidney hypertension because they can relax the blood vessels to a degree, which will improve blood flow. Additionally, if there is inflammation in the kidney, the fatty acids that are incorporated into many therapeutic kidney diets will help dampen the inflammatory effects. The amount of fish oil added to the food varies slightly between manufacturers, so talk to your vet to make sure you have the right food for your pet or if a supplement is necessary.
The effects of these fundamental changes in diet have been well-documented. Getting your pet on a therapeutic diet or food prescribed by your veterinarian will decrease the clinical signs associated with the disease and will significantly prolong your dog or cat’s life.
More on Kidney Disease
5 Facts About Kidney Failure
Symptons of Kidney Disease in Dogs and Cats
Treating Kidney Disease
This article was written by PetCareRx Consulting Nutritionist Dr. Joe, a board certified veterinary nutritionist and graduate of Cornell University's program for Veterinary Medicine. The information contained, however, is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian.