Feline Renal Protective Diet

Common in older cats, chronic renal failure involves a gradual, irreversible deterioration of kidney function over an extended period of time.

Kidneys use millions of tiny funnel-shaped tubes called nephrons to filter and reabsorb fluids. Damaged nephrons stop functioning; renal failure typically occurs when the functioning nephrons in a kidney drop below 25 percent, usually resulting in death.

Knowing what a cat needs in his diet for renal protection can greatly reduce the risk of this tragic disease.
  1. Cat Biology

    • Veterinarian Lisa A. Pierson says cats have evolved a biology that makes them naturally strict carnivores. In fact, they can't even use most plant proteins.

      Unlike humans and dogs, the bodies of cats cannot synthesize complete proteins from the incomplete protein building blocks found in non-animal, plant-derived sources such as grains and vegetables. In short, cats need meat.

      In the wild, cats tend to eat high-protein, high-moisture-content, meat-based diets, consisting of only about 3 to 5 percent carbohydrates. They eat small game such as rabbits, birds, rodents and certain juicy insects.

      Prey animals like these contain 70 to 75 percent water or more. Accordingly, cats have not evolved a strong "thirst reflex" like some other animals, and this can lead to low-level, chronic dehydration when dry food makes up the bulk of a cat's diet.

      You can aid in feline renal protection and the prevention of chronic renal failure by keeping these things in mind when choosing a food for your cat.

    Dietary Choices and Renal Protection

    • Dry food is convenient, and grain is cheap. And because convenience and affordability sell, you will find a vast array of agriculturally based, dry commercial cat foods.

      Read their labels. The first four or five listed ingredients constitute the bulk of the food. You will see most dry cat food contains 35 to 50 percent carbohydrates, while a cat only requires 3 to 5 percent.

      Remember, a cat's digestive system does not possess certain amylases and enzymes crucial to synthesize complete proteins from plant sources like brewer's rice, corn gluten meal and other vegetable products. This means they contribute little to his overall health.

      Pierson says even dry "renal protection" formulas and "urinary tract health" formulas prescribed by some veterinarians contain 10 percent water or less. Because cats should naturally get most of their water from their diet, they still face chronic dehydration from dry foods like these. This concentrates urine and actually aids in the formation of crystalline deposits in the kidneys that contribute to renal failure.

      Also, look at the "animal" ingredients in dry foods. Do they include "chicken byproducts" or "chicken meal?" Feathers, egg shells and chicken feet count as "byproducts" and are often ground into "meal." Cheap ingredients like these provide little nutritional value and do not contribute to good health. "Chicken" and "turkey" are better ingredients, even for dry food.

      Canned cat foods are much better for urinary tract health. At around 75 to 80 percent water content, they more closely approximate what your cat would get on his natural diet. Follow similar guidelines about "byproducts."

      Canned meat or fish is a fair choice, but not too much fish.

      Clean, fresh raw meat is best, and it cleans the cat's teeth, which are not designed to crunch kibble.

    Diet Transition

    • Like people, cats can develop quirks, habits and preferences, and often resist changes in their diet. In addition, cat food companies lightly spray inferior dry kibble foods with tantalizing animal products.

      Understandably, the transition to a meat-based or canned renal-protective diet may require some patience.