Understanding the dietary needs of cats diagnosed with chronic kidney disease (CKD) is crucial for their well-being. While there’s no cure for CKD, a carefully managed diet can significantly improve a cat’s quality of life and help slow the disease’s progression. This article explores the key nutritional considerations for cats suffering from kidney disease.
Understanding Chronic Kidney Disease (CKD) in Cats
The kidneys perform vital functions, including filtering waste from the blood, producing urine, regulating hormones, and maintaining fluid balance, electrolytes, pH, and blood pressure. CKD is characterized by a gradual and irreversible loss of kidney function, which can stem from various causes like infections, toxins, tumors, or often, with an unknown origin. While it can affect cats at any age, it is most commonly observed in cats over seven years old.
Recognizing the Symptoms of CKD
Several signs may indicate your cat is experiencing kidney issues. These include increased thirst and urination, lethargy, nausea, vomiting, decreased appetite, weight loss, elevated blood pressure, pale gums (due to anemia), a foul breath odor, and a dull, unkempt coat. It’s estimated that up to half of all cats over 15 years old exhibit some degree of CKD.
Diagnosis and Treatment of CKD
A veterinarian diagnoses CKD through a combination of blood and urine tests, and potentially kidney imaging. Blood tests reveal the buildup of waste products, while urine tests assess kidney concentration ability and check for infections. Monitoring your cat’s blood pressure is also a standard part of the diagnostic process. Treatment focuses on improving the cat’s quality of life and slowing the disease’s advancement. This involves managing nutrition, ensuring adequate hydration, maintaining electrolyte and pH balance, controlling blood pressure, and minimizing toxic waste accumulation, primarily through diet and medication.
Nutritional Management for Cats with CKD
Diet plays a pivotal role in managing CKD. Here’s what to look for in a cat’s diet:
Water Intake
Cats with CKD struggle to concentrate their urine, leading to increased water loss and potential dehydration. Encouraging water intake is paramount. Wet food, with its high moisture content (around 75%), is an excellent way to boost hydration. Furthermore, wet food is often more palatable and has a more appealing aroma than dry food, making it a better choice for cats with reduced appetites or nausea.
Phosphorus Levels
Restricting phosphorus in the diet is critical. High blood phosphorus levels (hyperphosphatemia) are linked to faster disease progression and are present in over 60% of cats with CKD. Low-phosphorus diets can help protect the kidneys, potentially extend lifespan, and reduce nausea. Foods with chicken or certain fish as primary protein sources are typically lower in phosphorus. Ideally, CKD diets should contain approximately 0.3-0.6% phosphorus on a dry matter basis. For severe cases, veterinarians may prescribe intestinal phosphate binders, though these can be stressful for the cat and owner.
Protein Quality and Quantity
Adequate protein is necessary to prevent muscle loss, but the breakdown of dietary protein produces waste products that overburden compromised kidneys, leading to nausea. Therefore, a diet with restricted but high-quality protein (ideally 28-35% on a dry matter basis) is recommended. High-quality protein is more digestible and helps maintain muscle mass. The exact protein requirement depends on the CKD stage. Reducing protein also helps lower overall phosphorus intake, as many meat proteins are high in phosphorus.
Caloric Density
To counteract reduced appetite and prevent weight loss, CKD diets are often calorie-dense. Higher calorie content helps compensate for smaller meal sizes and can enhance palatability and aroma. Individual calorie needs vary based on the cat’s weight, body condition, and the stage of CKD.
Sodium Content
Cats with CKD generally require diets with less than 0.4% sodium on a dry matter basis. Moderately restricted sodium intake can aid in managing high blood pressure associated with kidney disease.
Potassium Levels
Hypokalemia (low blood potassium) is common in CKD cats due to increased excretion by failing kidneys. Some therapeutic diets offer higher potassium levels, but supplementation should always be guided by a veterinarian who can assess individual needs through blood tests.
Omega-3 Fatty Acids
Known for their anti-inflammatory properties, omega-3 fatty acids may offer a protective effect on the kidneys by helping to maintain blood flow and reduce inflammation. An ideal CKD diet would contain 0.4-2.5% omega-3 fatty acids on a dry matter basis.
Antioxidants and Fiber
Antioxidants, such as vitamins C and E, can help protect kidney cells from damage. Soluble fiber promotes healthy gut bacteria, aiding in waste elimination through stool and helping to prevent constipation, a frequent issue in CKD cats.
Conclusion
While a CKD diagnosis can be distressing, understanding the nutritional management is key to supporting your cat. Your veterinarian is your primary resource for navigating treatment and dietary choices tailored to your cat’s specific needs. Ensuring your cat eats sufficiently is paramount, as the negative effects of weight loss can be more detrimental than consuming a non-therapeutic diet. Special renal diets are available, but if your cat refuses them, some regular diets may still meet CKD requirements. Always consult your veterinarian to confirm a diet’s suitability for your individual cat.
Notes from the team at Zealandia:
Zealandia’s canned food products are formulated with a high meat and organ content (95%, excluding processing water). A typical ingredient breakdown includes:
Deboned Meat: ~61.5%
Lamb Organs: ~30% (Liver, Lung, Green Tripe, Heart, Kidney, Plasma)
NZ Green Mussels: ~3%
Dried Yeast: ~3%
Vegetable Gums: ~1% (Guar Gum, Agar Agar)
Salmon Oil: ~0.5%
Vitamins & Minerals: ~1% (Calcium Carbonate, Potassium Chloride, Taurine, Choline Chloride, Iron Proteinate, Zinc Glycine Complex, Niacin Supplement, Alpha-Tocopherol Acetate, Sodium Selenite, Manganese Proteinate, Copper Glycine Complex, Thiamine Mononitrate, Calcium Pantothenate, Riboflavin, Pyridoxine Hydrochloride, Vitamin A Acetate, Biotin, Vitamin B12 Supplement, Calcium Iodate, Folic Acid, Cholecalciferol)
The Zealandia variants most suitable for cats with a history of CKD are: Salmon (Adult) and Salmon (Kitten), due to their low phosphorus, lower protein, moderate to high energy, low sodium, and high fat content.
View the Zealandia Cat Food Nutrition Profile (PDF)
Note: Lamb recipes produced prior to July 2025 have a lower phosphorus content.
