A concerning study from 2017 has shed light on a significant dietary factor that can negatively impact feline kidney function. Research indicates that elevated phosphorus levels in commercial cat food can not only exacerbate existing chronic kidney disease (CKD) in diagnosed cats but also potentially damage the kidneys of healthy felines. This revelation is particularly critical given that over half of pet cats aged 10 and older are estimated to suffer from some form of CKD.
The study, published in the Journal of Feline Medicine and Surgery, investigated the effects of high phosphorus intake on both healthy and kidney-compromised cats. The findings suggest that the common practice of including high phosphorus levels in cat food, often from natural sources like bone and cereal or added inorganic phosphates for texture and shelf life, may be a significant contributor to the high incidence of kidney disease in cats. This information is vital for pet owners looking to provide the best nutrition and long-term health for their feline companions.
Understanding the Link Between Phosphorus and Kidney Damage
Chronic kidney disease (CKD) is a progressive condition that affects a large percentage of the aging feline population. While various factors contribute to its development, the 2017 study highlights the detrimental role of excessive phosphorus in commercial cat diets. Researchers observed that even healthy cats fed a diet high in phosphorus showed markers of kidney damage, including glucosuria (high glucose in urine) and albuminuria (high albumin in urine). Furthermore, their creatinine clearance, a key indicator of kidney function, significantly decreased within a short 28-day period.
Professor Ellen Kienzle, the study’s lead author, stated that these results strongly suggest excess phosphate adversely affects kidney function indicators and could be a contributing factor to the prevalence of CKD in older cats. The study also revealed that canned cat foods tested in Germany contained phosphorus levels up to nine times higher than what cats require, a level the researchers believe could damage healthy kidneys within weeks.
Foods and Ingredients to Avoid for Kidney Health
Based on the research and expert recommendations, certain types of cat food and ingredients should be approached with caution to protect your cat’s kidneys:
Dry Cat Food (Kibble)
Kibble is often flagged for its low moisture content. Cats, by nature, are adapted to obtain most of their water from their diet, and kibble provides very little. This can lead to chronic mild dehydration, placing significant stress on the kidneys over time. Additionally, the protein quality in many dry foods is often poor, derived from rendered, feed-grade ingredients that can be harder for cats to digest, potentially stressing the liver and kidneys. For cats with compromised kidney function, this lack of hydration is particularly concerning. If you’re considering alternatives, explore options like high calorie cat wet food or other moisture-rich options.
Cat Food Containing Meat Meal
While aging cats may require more protein, it must be of high quality and without excessive phosphorus. Meat meals (e.g., chicken meal, fish meal), which are primarily ground bones and connective tissue, can contain high levels of phosphorus and calcium. Muscle meat is typically removed before rendering, making meat meals a less-than-ideal protein source for kidney health. Ensuring your cat receives adequate protein from quality sources is essential.
Prescription Renal Diets (Certain Types)
Many prescription renal diets, particularly dry formulas made from rendered ingredients, do not meet a cat’s critical hydration needs. This is especially problematic for cats already losing significant water through compromised kidneys. While beneficial for managing CKD, it’s crucial to discuss the formulation and moisture content of prescription diets with your veterinarian. Some cats on these diets may require supplemental fluids. For cats needing enhanced caloric intake, options like high calorie dry cat food for weight gain might be considered under veterinary guidance, but always prioritize moisture.
Recommended Diets for Kidney Support and Prevention
For Cats Diagnosed with CKD
A human-grade, fresh food diet formulated with lower phosphorus levels is recommended for cats with CKD. This can be homemade or a commercially prepared option specifically designed for kidney disease. Ensuring a diet that is both nutritionally balanced and species-appropriate is paramount.
For Cats with Healthy Kidneys
For felines with healthy kidneys, a varied diet is key. This can include a combination of:
- Homemade raw or cooked food.
- Commercially available balanced raw, dehydrated raw, or freeze-dried raw (reconstituted) options.
- Human-grade canned food.
Exploring options such as nutritious dry cat food as part of a varied diet, in consultation with a vet, can be beneficial. A comprehensive chart detailing phosphorus levels in various cat foods is available from resources like CatInfo.org. Remember to prioritize high-quality protein sources and species-appropriate nutrition.
Additional Support for Cats with CKD
Beyond diet, several other supportive measures can benefit cats with CKD:
- Supplementation: B vitamins can help with anemia, nausea, and overall well-being. Antioxidants, L-carnitine, and medium-chain triglycerides (like coconut oil) may also be beneficial. Blood-building supplements such as chlorophyll or chlorella, and detoxification support like n-acetyl cysteine (NAC), dandelion, and SOD can be considered. Probiotics with specific kidney-supportive strains can aid in healthy urea metabolism. Kitten supplement options, tailored for specific needs, should be discussed with a veterinarian.
- Stress-Free Environment: Minimizing stress is crucial for a cat’s overall health and can positively impact their recovery and well-being.
- Regular Monitoring: Vigilant monitoring of organ systems by a veterinarian is essential for early detection of risks and subtle changes, allowing for proactive management before kidney failure occurs. Your vet can help determine if supplements like liquid diet for cats or others are appropriate.
By understanding the impact of phosphorus and making informed dietary choices, owners can significantly contribute to their cat’s kidney health and overall longevity. Early detection and proactive management are key to ensuring cats with kidney disease can live long, fulfilling lives.
