Can Healthy Cats Eat Renal Food?

Have you ever caught your cat red-pawed, sneaking a nibble (or entire meal) from their sibling’s bowl? It seems the first rule of feline feasting is that stolen food tastes better. For this reason, it’s certainly easier to feed all your feline friends the exact same pet food. However, when one cat is on a special renal food diet for an issue like chronic kidney disease (CKD), things get a bit more complicated.

We talked with three veterinarians to learn the ins and outs of renal food diets and to get answers to our most pressing questions, including: Can healthy cats eat renal food? What’s the difference between regular cat food and renal food? And how in the heck do we feed cats separately?

Renal cat food “is specifically formulated to support the kidney function of cats with renal issues,” says Bethany Hsia, DVM, co-founder of CodaPet, which has locations in over 10 US cities.

“Cats can experience a range of kidney issues that may necessitate the use of renal foods,” Dr. Hsia says. “These issues include chronic kidney disease [CKD], acute kidney injury, and nephrolithiasis [the formation of kidney stones].”

Sara Ochoa, DVM, veterinarian at Animal Hospital of West Monroe in Louisiana, says renal cat food differs from traditional cat food in the following ways:

• Reduced phosphorus levels: A cat’s ability to process phosphorus is often impaired by kidney disease. In turn, high levels of phosphorus can stress the kidneys. Renal food, therefore, is lower in phosphorus to help protect the cat’s kidneys, thus slowing the progression of kidney disease and helping to preserve renal function and prevent renal failure.
• Different protein quality and quantity: Cats are carnivores, and a protein diet is essential for them. However, when a cat has chronic kidney disease, they need a different type and quality of protein. Specifically, renal food contains high-quality protein in controlled amounts. “This can help reduce the buildup of waste products that kidneys would otherwise have to filter, ensuring your cat gets the nutrients they need without overworking their kidneys,” Dr. Ochoa says.
• Increased potassium content: To address the low potassium levels that cats with kidney disease often experience, renal diets have more potassium than traditional cat food.
• Inclusion of omega-3 fatty acids: Many renal diet cat foods contain omega-3 fatty acids because research has shown “they can have anti-inflammatory effects and may help improve kidney function,” Dr. Ochoa says.
• Altered alkaline properties: Cats with kidney disease can have a more acidic internal environment. “Renal foods are frequently designed with an alkalinizing effect, reducing acidity and helping prevent uncomfortable conditions like the development of kidney stones,” says Dr. Ochoa.

Yes, healthy cats can occasionally eat renal food without experiencing serious adverse effects. This means that if your healthy cat sometimes sneaks a bite (or an entire meal) from your cat who is on a renal diet, you have nothing to worry about (beyond potential GI upset from the new food).

Healthy cats should not, however, eat a consistent renal food diet, and they should not be placed on a permanent renal veterinary diet. This is because the ingredient quantities in renal cat food are different from those in typical cat food.

Additionally, because of the altered ingredients in foods formulated for cats with CKD and other renal issues, Dr. Hsia says that if a healthy cat were to be placed on a long-term renal cat food diet, they could suffer ill effects. She notes the following concerns:

• Essential nutrient deficiencies: Lower phosphorus and other nutrient levels in renal diets can lead to nutritional imbalances in healthy cats.
• Weight loss or muscle wasting: Cats are carnivores, and they need a protein diet. However, the protein content in renal diets is lower than in typical cat food. Healthy cats may experience weight loss or even muscle wasting if they eat a long-term renal diet.
• Digestive issues: Abruptly changing a healthy cat’s normal food to a renal food could lead to digestive upset, including vomiting, diarrhea, and/or decreased appetite. These issues aren’t limited to switching between normal food and renal. They can occur any time a new food is substituted for your cat’s regular food.

Renal cat food is formulated to be extra tasty since cats with kidney issues tend to have a lower appetite, Dr. Ochoa says. This can make renal food even more tempting to your healthy cat, increasing the likelihood they’ll indulge in your other pet’s food.

Don’t be discouraged, though, because it is possible to feed your cats separately to ensure they eat their own food. Sabrina Kong, DVM, veterinarian at a small animal clinic in Northern California, offers the following strategies:

1. Feed cats in different rooms: Dr. Kong says feeding cats in different rooms and/or at different heights allows cats to enjoy mealtime without interruption or food theft.
2. Feed cats at different heights: If your cat needing the special diet is older and can’t or doesn’t like jumping, you can place their food on the floor and place your other, more agile cat’s food on a higher surface area, like a table or shelf.
3. Use timed feeders: Timed feeders serve controlled portions at set times to each of your cats. Note that many timed feeders are intended for use with dry kibble and only some can accommodate canned food. Be sure to read the product description so you can select one that fits your feline friends’ needs.

If you want to take the timed feeder route, consider the Frisco® Automatic Feeder for dry food or the Closer Pets™ One-Meal Automatic Timed Feeder, which can be used for canned food or dry kibble.

Remember that when feeding cats separately, “consistency and routine in feeding times and locations can help cats adapt to this arrangement,” Dr. Kong says.

Use these separate-feeding tips to ensure all your cats maintain quality of life. It’s possible to accommodate one cat’s special diet while ensuring the healthy cat gets the nutrients they need.

If your cat needs a special prescription diet for chronic kidney disease, it’s important to choose high-quality canned food or dry food.

Dr. Ochoa recommends the following brands of prescription diet foods for cats with CKD. Of course, always check with your vet before switching your cat’s food.

“This veterinary therapeutic diet contains controlled phosphorus, protein and sodium levels to help support kidney function,” Dr. Ochoa says. “The blend of antioxidants, omega-3 fatty acids, and vitamins also helps maintain a healthy immune system.”

“This kidney diet manages mineral levels, including phosphorus and sodium, and provides high-quality protein sources. It also contains omega-3 fatty acids to help reduce inflammation,” Dr. Ochoa says.

“This food helps maintain muscle mass with high-quality proteins,” Dr. Ochoa says. “It also contains an optimal phosphorus, sodium, and potassium balance to support kidney health. Antioxidants help maintain a healthy immune system.”

Dr. Hsia answers some FAQs about renal diets for cats with CKD and other kidney-related issues.

When it comes to prescription diet renal food, how do canned food (wet food) and dry cat food compare?

While both types of foods are formulated to be nutritionally sound for cats on renal food diets, Dr. Hsia says each type of food has its advantages:

Dry kibble (or dry food):

• Longer shelf life
• More affordable

Canned food (or wet food):

• Higher moisture content
• Lower protein content
• Easier to digest

Should cats on a renal support diet take any supplements?

Dr. Hsia recommends the following three supplements for cats on special diets for their kidneys. However, as always, check with your vet before starting any supplements for your cat.

1. “Omega-3 fatty acids have anti-inflammatory properties and can help reduce inflammation in the kidneys, which can be beneficial for cats with chronic kidney disease [CKD]. You can find omega-3 fatty acids in fish oil supplements or flaxseed oil supplements,” Dr. Hsia says.
2. “Vitamin E is an antioxidant that can help improve the function of the kidneys and reduce the risk of complications such as kidney failure.”
3. “L-carnitine is an amino acid that can help reduce the amount of waste products in the blood and improve the function of the kidneys. It can also help reduce the risk of complications such as heart disease.”

While it’s not the simplest task, it’s important to feed your cats separately when one is on a renal diet because, while a healthy cat can eat a little bit of renal food without serious adverse effects, they shouldn’t be on a long-term renal food diet. Learn more about your cat’s urinary and kidney health.

Expert input provided by Bethany Hsia, DVM, co-founder of CodaPet; Sara Ochoa, DVM, veterinarian at Animal Hospital of West Monroe in Louisiana; and Sabrina Kong, DVM, veterinarian at a small animal clinic in Northern California.

This content was medically reviewed by a veterinarian.