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Coming to grips with a kidney disease diagnosis for your cat can be tough. But there are lots of reasons to be hopeful, especially since when chronic kidney disease is spotted early, your cat can have many more years to enjoy. One way to help extend their life is to start them on a diet of cat food low in phosphorus.
Three out of 10 geriatric cats (age 15 or older) will receive a diagnosis of chronic kidney disease. My deaf white cat, Sheba, was diagnosed at age 14. She went on to spend more than four more happy years chasing the other cats in our household and swatting vases off the mantelpiece.
In this article, we take a look at chronic kidney disease in cats (also called chronic renal failure) and the low-phosphorus diet for cats recommended by many veterinarians to slow the progression of the disease.
Understanding Kidney Disease in Cats
Kidney disease in cats can be caused by a bacterial infection, but often the exact cause remains unknown. For whatever reason, your cat’s kidneys stop doing their job of removing waste products, such as proteins and phosphorus, and excreting them in urine. As a result, the cat’s systems are thrown out of balance. All sorts of problems can occur, from high blood pressure to anemia.
What are the first signs of kidney disease? Your cat may show increased thirst or begin urinating more frequently. Though they eat normally, you may see subtle weight loss. As the disease progresses, some cats may experience a decreased appetite, more severe weight loss, lack of energy, and poor grooming habits.
Kidney disease is not curable, but if the condition is caught early on, a healthy diet can enable cats to live a long life. As the condition progresses, cats may be given phosphorus-binding drugs before meals, subcutaneous fluids, and other medications. But let’s start with the food.
Why Get a Cat Food Low in Phosphorus?
A low-phosphorus diet is designed to reduce kidney workload and improve health. Research shows that cats with chronic kidney disease fed a low-phosphorus diet can live up to twice as long as cats with no dietary changes.
The best cat food for cats with chronic kidney disease will reduce kidney workload by moderating protein, carbohydrate, and phosphorus intake. Because poor kidney function allows acids to build up, kidney diets are alkaline, helping to neutralize harmful acids.
“Kidney diets are actually very different from regular cat food,” explained Dr. Joe Wakshlag, veterinarian and professor at Cornell University College of Veterinary Medicine in a video previously shared on the school’s YouTube channel. “They have reduced levels of phosphorus and protein, and they have increased levels of potassium, B vitamins, and fatty acids.”
It’s always a good idea to introduce any new cat food, including low-phosphorous food, gradually by mixing it in with your cat’s regular food. Over time, your cat can be switched fully to the low-phosphorus diet. If they get tired of one brand of low-phosphorus food (as cats do), you can introduce another or cycle through several different kinds.
As you’re trying out new foods, avoid foods labeled “urinary diets” unless they’re recommended by your veterinarian. Those are designed to prevent the formation of kidney stones—a very different condition—and can actually aggravate kidney disease in cats.
The Best Cat Food Low in Phosphorus
You’ll find two types of low-phosphorus foods on our list of favorites:
- Prescription veterinary diets with carefully calibrated amounts of phosphorus, sodium, protein, minerals, vitamins, and fatty acids. These are usually alkaline, rather than acidic, foods.
- Low phosphorus foods that include premium, natural ingredients but do not claim to address the range of kidney issues that prescription foods are designed to treat.
You’ll want to check with your vet to see what they recommend for your cat. For prescription foods, you’ll have to provide a prescription or your veterinarian’s contact information to purchase. Your vet often can offer their advice on non-prescription foods as well, ensuring that the food you choose meets your cat’s individual needs. Depending on your cat’s prognosis and any other health concerns that may be present, some non-prescription foods may not be recommended.
Because cats with kidney disease tend to lose weight, Royal Canin has formulated this low-phosphorus pâté in gel to be as tasty and enticing as possible. In addition to the pâté, Royal Canin makes other renal support formulas including D (morsels) and T (slices), and it’s worth experimenting to see if your cat prefers one over the others. Prescription required.
This prescription diet is designed to protect kidney and heart function while boosting your cat’s energy and vitality with targeted levels of high-quality protein and controlled phosphorus. Prescription required.
Available in both dry and wet forms, this veterinary diet is a nutritious low-phosphorus and low-sodium food for cats. The Blue Buffalo brand focuses on preservative-free natural ingredients. Prescription required.
This specially formulated wet food contains a moderate amount of high-quality protein and restricted phosphorus. It can be combined with the kibble version of this diet if your cat enjoys dry food. Purina also makes an Advanced Care formula. Prescription required.
If you are trying to find a low-phosphorus cat food your cat will like, it may be worth giving Forza10 a try; it aims to put great taste into a food that’s healthy for cats with renal disease. The appealing recipe was developed by veterinarians and nutritionists in Iceland, but you can get it without a prescription. Plus, Forza10 has a dry food for cats with kidney disease available as well. No prescription needed.
Weruva Truluxe Steak Frites is not a veterinary kidney disease formula, but it is low in phosphorus and sodium. If your cat is turning up their nose at some of the other low-phosphorus foods, this could be a good choice to keep them interested in eating. Check with your vet to make sure they’re OK with feeding it to a cat with early-stage renal disease. No prescription needed.
Produced in a human-grade food manufacturing facility, this canned food recipe is low in fat and phosphorus but includes high-quality animal protein from chicken. It’s not a prescription food, so check with your vet to see if the phosphorus level will work for your kitty. No prescription needed.
This food from Wellness isn’t specifically designed for cats with renal disease, its grain-free, high protein, and relatively low-phosphorous recipe makes it an option for some. It’s especially appealing to cats who like chunky foods. Your vet can help you decide if it’s right for your cat. No prescription needed.
While not marketed as therapeutic food for cats with renal issues, this food from Hill’s Science Diet does have relatively low phosphorus (0.52 percent). Consult with your veterinarian to see if they think this is appropriate for your cat. No prescription needed.
Tips for Homemade Low-Phosphorus Cat Food
Cats with moderate to severe kidney disease sometimes become picky eaters. If packaged foods don’t work for your kitty, a homemade diet may be the best option.
It’s not always a good idea to grab a recipe off the internet, even if it’s touted as being great for a cat with kidney failure. Instead, consult with a veterinarian or a credentialed veterinary nutritionist—they’ll have a recipe or two that will be safe and effective for your cat.