My 10-year-old cat was just diagnosed with chronic kidney disease, and I was told she needs to eat special food. What does this mean for her?
chronic kidney disease (CKD) is the most common kidney disease in cats. waste products are normally filtered from the blood by the kidneys and excreted in the urine, but cats with ckd will end up with a buildup of these waste products in their bloodstream as the filtration process breaks down. For more information on this condition, see the brochure “Chronic Kidney Disease in Cats”.
Nutrition plays an important role in the management of CKD in cats. There are four main goals for managing CKD in cats:
- manage clinical signs associated with the accumulation of waste products in the blood
- minimize problems with fluid and mineral balance
- maintain proper nutrition
- modify/slow down the progression of CKD
nutrition addresses all of these goals. commercial diets for ckd cats are developed to prioritize these key goals. Compared to normal maintenance adult cat food, a kidney support diet contains less protein, sodium and phosphorous, and more omega-3 fatty acids. These diets are formulated to help cats with CKD avoid metabolic acidosis and are available through your veterinarian. Examples include Hill’s® Prescription Diet® K/D® (both early and late diets are available), Royal Canin® Renal Support, Purina® ProPlan® Veterinary Diet NF Renal Function®, and Rayne Clinical Nutrition™ Adult Health-RSS ™
how do the nutritional requirements of cats with ckd differ?
Water. Diseased kidneys are not as effective at excreting waste products from the body through urine. one consequence of ckd is a decreased ability of the kidneys to concentrate urine. In order to continue removing toxins from the body despite the more dilute urine, the body compensates by stimulating greater thirst. this makes it essential that you provide your cat with an unlimited supply of fresh water. canned food can help increase your cat’s moisture intake. To encourage increased water intake, change your pet’s water several times a day, clean your pet’s water bowl daily, and consider using a running water source to increase interest in water.
protein. Decreasing protein in the diet may slow the progression of chronic kidney disease by decreasing the workload on the kidneys to excrete protein waste products. Less protein also means less need for protein excretion through the kidney’s filtration mechanism, which helps preserve kidney function. the recommended range of protein on a dry matter basis for cats with ckd is 28-35%. however, if protein intake is too low, ckd will start to break down muscle mass.
Phosphorus. Limiting phosphorus in the diet of cats with ckd appears to help slow the progression of ckd, although the precise mechanism is unknown. it also serves to reduce the effects of secondary renal (kidney) hyperparathyroidism. the recommended range of phosphorus on a dry matter basis for cats with ckd is 0.3-0.6%. since phosphorus content is related to protein content, it is impossible to achieve these lower phosphorus levels without limiting protein content.
Sodium. Dietary sodium levels are slightly restricted to reduce the workload on the kidneys. this in turn helps maintain a reasonable blood pressure.
Omega-3 fatty acids. Dietary omega-3 fatty acids help reduce the production of inflammatory compounds that create oxidative stress in diseased kidney tissue, contributing to delayed the progression of chronic kidney disease. this works by reducing the “leakage” of protein through the kidneys.
how can I make good nutritional choices for my cat with ckd?
a kidney support diet for cats with ckd will contain the following key components on a dry matter basis:
Your vet will help you choose a suitable formulation for your cat. Maintaining proper caloric density is critical to maintaining good body condition, so food portion calculations and regular weigh-ins are important.
Commercially available kidney support diets tend to be quite palatable because it is very important that these cats eat in a way that slows the progression of their chronic kidney disease. if necessary, adding water, tuna juice, or low-sodium chicken broth can increase flavor and acceptance. your vet is your best resource in determining the best nutritional option for your cat as chronic kidney disease progresses.
