Important Components of Renal Diets
Chronic Kidney Disease (CKD), is one of the most common diseases seen in geriatric cats. In the cat, this disease is often only detectable after 70% or more of kidney function has been lost, meaning that controlling and delaying symptoms is especially important. Kidney disease limits the body’s ability to effectively process, concentrate, and eliminate wastes, leading to increased urine output and increased thirst to compensate for this. Perhaps, fortunately, however, kidney disease is one of the few conditions in elderly cats which is best treated by a prescription diet rather than medication.
Here are the important components of a renal diet for cats
Water: Constant provision of water is the most essential component of managing kidney disease with clinical nutrition. Because the kidneys’ ability to concentrate and eliminate wastes is compromised in cats with CKD, these cats need to drink more water in order to eliminate the same amount of wastes from the body. Cats with CKD should have multiple sources of water available in the house, and novelty water sources like feline drinking fountains can help entice these cats to drink the water they need. Feeding canned or wet food can also help increase water intake for these cats, and is highly recommended for all cats that will eat wet food.
Protein: The first important component of a renal (kidney) diet is reduced protein content. Reducing the amount of protein present in the diet reduces the amount of work for the kidneys in processing wastes, which slows the rate of progression and helps delay the worsening of symptoms. However, because cats require fairly high dietary protein to maintain muscle mass, protein levels in a renal diet cannot be too low, or nutritional deficiencies will result.
Phosphorus: As with protein, limiting phosphorus content in the diet reduces the workload on the kidneys. Phosphorus content correlates with protein content, so a lower-protein diet will also contain less phosphorus. However, the reason why this lowered phosphorus content helps the kidneys is currently unknown.
Sodium: Limiting sodium, as with phosphorus and protein, lessens the strain on the kidneys. This also helps keep the blood pressure within normal limits, thereby also minimizing strain on the cardiovascular system and the rest of the body.
Omega-3 Fish Oil: These oils have been shown to have some effect in protecting kidneys in the dog, though no studies have been formally done in cats. However, these oils have been used to good effect in feline kidney patients, though they should only be used in otherwise stable patients due to the risk of anemia (as they can reduce platelet adhesion) as a side effect.
Below are the recommended nutritional ranges of the above-mentioned elements for the renal diet by percentage.
Protein: 28% – 35%
Phosphorus: 0.3% – 0.6%
Sodium: Less than 0.4%
Omega-3 Fatty Acids
0.4% – 2.5%
While there are other elements of renal nutrition in the cat, those are beyond the scope of this article. In effect, however, the primary focus of the renal diet is to decrease the amount of work the kidneys have to do to process the diet, thereby lessening the strain on the organs and preserving kidney function for as long as possible. Several reputable brands make prescription veterinary diets, including Hill’s kd range, whose k/d diet is a staple in veterinary hospitals, and Royal Canin’s Renal Diets in multiple flavors to entice picky eaters.
Contact us and ask one of our vets to help you determine the best diet for your pet with kidney or renal problems.
Written by: Laurel Osgood, ABVC Veterinary Nurse
