Chronic renal (kidney) failure in cats is a common problem as pets age, especially those who have been fed a diet of primarily dry cat food. Switching to homemade cat food may provide the best chance for recovery.
Once your cat is on the staple food, add cut vegetables for fiber and nutrients. Steamed mashed carrots, potato peelings, frozen peas, and fresh spinach or kale are acceptable. Do not use cooked spinach, and do not give your cat onions.
Spirulina is a blue-green algae nutrient that some cats love. Others will take small amounts mixed with food. Baby food, while not prepared with a cat’s nutritional need in mind, is sodium-free and can be used to optimize calories.
High quality protein
The cat usually eats fish, birds, and small rodents that have partially ingested greens, seeds, and other plant materials in their crops, stomach, and intestines. They were swallowing the flesh of organs and bones. None of the meat or vegetables would be cooked through.
Try chicken hearts and bars, eggs and turkey mixed with wheatgrass or spirulina juice, non-dairy probiotic and enzyme supplements, and alfalfa sprouts. Experiment with what the cat will accept, especially if it is used to dry kibble. To lower phosphorus, avoid milk and beef. Offer fresh filtered or distilled water to drink.