Cat Nutrition · July 7, 2026 · 4 min read

Can Cats Eat Tuna?

Cats love tuna, but a diet of tuna alone can cause real nutritional problems. Here's how to offer it safely as an occasional treat.

Most cats find tuna irresistible, and a small amount of plain, cooked or canned-in-water tuna is generally safe as an occasional treat. The problem is that tuna isn't nutritionally complete for cats, and it can cause specific health issues if it becomes a regular part of the diet rather than a rare extra.

Why tuna shouldn't be a regular meal

Tuna is high in unsaturated fat and low in some nutrients cats need in balance, particularly vitamin E. Feeding tuna as a steady diet has been linked to a painful condition called steatitis (yellow fat disease) from a vitamin E deficiency, as well as mercury accumulation over time since tuna -- a large predatory fish -- carries more mercury than many other proteins.

Commercial cat food labeled 'tuna flavor' is formulated to be nutritionally complete, which is different from feeding plain tuna as a regular meal.

How to serve it safely

A small amount of plain tuna (packed in water, no added salt or oil, and never raw for safety reasons) once in a while is a reasonable treat for most healthy cats. As with any treat, keep it to a small share of daily calories so it doesn't crowd out a balanced diet.

Who should avoid it

Cats with kidney disease, urinary issues, or a history of pancreatitis are often advised to avoid tuna, since its phosphorus and fat content can aggravate those conditions -- check with your vet for a cat with any of those diagnoses.

Calculations follow the NRC RER/MER methodology, aligned with WSAVA & AAHA guidelines.

Frequently Asked Questions

Medical Disclaimer

This tool provides general, educational estimates and is not a substitute for professional veterinary advice, diagnosis, or treatment. This article provides general educational information and is not a substitute for professional veterinary advice. Always consult your veterinarian about your pet's specific health needs before making changes to their diet, water intake, or care routine.

Put This Into Practice

Sources

  • ASPCA Animal Poison Control Center
  • American Association of Feline Practitioners (AAFP)