Hills Prescription Diet I/D Cat Food: A Buying Guide

By PDSA Pet Store | Published: 2026-10-14

Category: Product Reviews

Hills Prescription Diet I/D is a vet-recommended digestive care cat food for cats with GI or liver issues. Learn when it helps and how to choose.

Quick answer

Hills Prescription Diet I/D is a therapeutic cat food formulated to support digestive health and liver function, and it's typically recommended by veterinarians for cats with gastrointestinal upset, liver conditions, or recovery needs. If your vet has diagnosed a digestive or liver issue, this diet can be a key part of management. For healthy cats without a specific diagnosis, a regular maintenance diet is more appropriate.

What makes I/D different from regular cat food?

Hills Prescription Diet I/D is not a standard maintenance diet. It's a therapeutic formula designed to be gentle on the digestive system while providing complete and balanced nutrition. The recipe typically includes highly digestible ingredients to reduce the workload on the gut, plus added nutrients that support the liver's natural detoxification and repair processes. Because it's a prescription diet, it should only be used under veterinary supervision.

When your vet might recommend I/D

Vets often turn to I/D for cats recovering from vomiting, diarrhea, or other gastrointestinal disturbances. It's also used for chronic conditions like inflammatory bowel disease, pancreatitis, or liver disease. If your cat has been diagnosed with a condition that affects digestion or liver function, I/D can help manage symptoms and support recovery. Always follow your vet's feeding instructions, including how long to feed the diet and when to transition back to regular food if appropriate.

How to transition your cat to I/D

Switching to a new food should be done gradually to avoid upsetting your cat's stomach. Start by mixing a small amount of I/D with your cat's current food, then slowly increase the proportion of I/D over 7 to 10 days. If your cat is recovering from a digestive issue, your vet may recommend a faster transition or a temporary exclusive feeding of I/D. Monitor your cat for any signs of intolerance, such as vomiting or diarrhea, and contact your vet if they occur.

Decision rules for choosing I/D

If your cat has acute digestive upset: Vets often recommend I/D for short-term management of vomiting or diarrhea. Feed as directed, usually for 1-2 weeks, then reassess with your vet. Use for short-term recovery under vet guidance.
If your cat has chronic GI or liver disease: I/D can be part of long-term management. Your vet will determine if it's suitable based on your cat's specific condition and may combine it with other treatments. Long-term use requires ongoing veterinary supervision.
If your cat is healthy with no diagnosed issues: A prescription diet like I/D is unnecessary and may not provide the right balance for a healthy cat. Choose a high-quality maintenance diet instead. Don't use I/D without a vet's recommendation.

Product facts

Hills Prescription Diet I/D Liver Care Dry Cat Food - 1.5kg: Hills Prescription Diet I/D Liver Care Dry Cat Food is formulated to support liver function, which is vital for metabolism, toxin removal, and nutrient storage. The liver can repair and regenerate, and nutrition plays a key role. If your cat has liver issues, this diet provides targeted nutritional support that regular food may not offer.
Hill's Science Plan Perfect Weight & Active Mobility Small Adult Dog Dry Food: Hill's Science Plan Perfect Weight & Active Mobility Small Adult Dog Dry Food is clinically proven to help with weight loss and joint support for small dogs. If you also have a small dog that needs to lose weight or stay mobile, this formula addresses those needs, but it's not for cats.