Phosphorus Restriction (Cat Food)
Definition
Phosphorus restriction in cat foods refers to the limitation of dietary phosphorus to below concentrations of 0.5% on a dry matter basis for senior cats, and 0.3% for cats with chronic kidney disease (CKD) Stage 2 or higher. In the cat, restriction of dietary phosphorus has been demonstrated to slow the rate of renal tubular damage and slow the progression of CKD. The International Renal Interest Society (IRIS) recommends restriction of dietary phosphorus as a primary nutritional intervention for all IRIS CKD classified Stage 2–4 cats.
Expanded Body
Nutritional restriction of phosphorus is one of the most well-supported nutritional modifications used in feline patients and for senior or geriatric cats with Chronic Kidney Disease (CKD) selecting a suitable cat food with low phosphorus content is an important consideration. The International Renal Interest Society (IRIS) Staging System for CKD in Cats (2023 revision) states that CKD is a common disease in cats with 31-49% of cats over 15 years of age affected by the disease. In the cat, the kidneys are the primary route of excretion of phosphorus. Therefore, as the kidneys of a cat with CKD fail, serum levels of phosphorus will increase to cause hyperphosphatemia. Hyperphosphatemia can cause damage to the renal tubular cells and also cause elevation of parathyroid hormone (PTH) levels which in turn can cause further decline in renal function.
Normal adult feline diets contain 0.6–1.2% phosphorus (on a dry matter basis). IRIS CKD Stage 2 cats (serum creatinine 1.6–2.8 mg/dl) are best fed on a diet with less phosphorus, less than 0.5% on a dry matter basis. IRIS CKD Stage 3 and 4 cats (serum creatinine > 2.8 mg/dl) are best fed on a diet with reduced amounts of dietary phosphorus, less than 0.3% on a dry matter basis. None of the over-the-counter renal diets are available in India. However, there are several prescription diets which are available through registered Hills and Royal Canin Veterinary Distributors all over India including Bengaluru, Mumbai and Delhi. These products would need a prescription from a veterinarian. The prescription diets available are Hills Prescription Diet k/d Feline (0.26% DM phosphorus), priced at approximately ₹3,800 for a 1.5 kg case and Royal Canin Renal (0.31% DM phosphorus), priced approximately at ₹3,200 for a 2 kg case.
Quick Facts
| Metric | Value |
|---|---|
| Normal Adult Cat | 0.6–1.2% DM |
| IRIS CKD Stage 2 | < 0.5% DM |
| IRIS CKD Stage 3–4 | < 0.3% DM |
| CKD Prevalence (15+ yr) | 31–49% |
| India Renal Diets | Hills k/d, RC Renal |
PHOSPHORUS IN CAT FOOD — INDIA BRANDS
| Cat Food Brand | Phosphorus % DM | Indicated For | Price (India) | Available At |
|---|---|---|---|---|
| Hills Prescription Diet k/d | 0.26% | IRIS CKD Stage 2–4 | ₹3,800/1.5 kg | Vet clinics, Amazon |
| Royal Canin Renal | 0.31% | IRIS CKD Stage 2–4 | ₹3,200/2 kg | HUFT, vet clinics |
| Hills Science Diet Senior 7+ | 0.62% | Healthy senior cats | ₹2,800/1.58 kg | Amazon, HUFT |
| Royal Canin Ageing 12+ | 0.55% | Geriatric cats (12+) | ₹3,200/2 kg | HUFT, Amazon |
| Drools Cat Adult (dry) | 0.9% | Healthy adult cats | ₹380/kg | DMart, BigBasket |
| Whiskas Pouch (wet) | 0.7% (estimated DM) | Healthy adult cats | ₹35/85g | DMart, Reliance Smart |
Related Terms
Faq
Q: When should I switch my cat to a low-phosphorus diet?
If your cat has been diagnosed with IRIS CKD at Stage 2 or above by your veterinarian, using a low phosphorus content cat food is recommended. Phosphorus restriction in healthy cats can decrease the absorption of calcium and so should not be used as a preventative for CKD. WSAVA recommends annual blood tests for all cats seven years of age and above in order to detect CKD early in healthy animals that have no symptoms of disease.
Key Takeaways
- Restricting phosphorus is the main nutritional management for feline CKD. This will help control hyperphosphatemia and slow the disease progress.
- IRIS targets for Senior cats with CKD Stage 2 are < 0.5% DM and for Senior cats with CKD Stage 3–4 are < 0.3% DM.
- 31–49% of older cats (15 years and older) are affected with chronic kidney disease (CKD). Managing phosphorus intake when selecting a senior cat food is crucial to the health of your senior feline.
- The various Indian veterinary renal diets available in the market are Hill’s k/d (DM phos 0.26%, Cost INR 3800/- for 1.5 kg) and Royal Canin Renal (DM phos 0.31%, Cost INR 3200/- for 1.5 kg).
