Can Cats Eat Tuna Daily? Mercury Risks
We usually think of tuna as the ultimate cat food. And while cats go crazy for the smell, a diet of just tuna is actually dangerous. Human Tuna is NOT Cat Food.
The 3 Key Dangers
1. Mercury Poisoning
Tuna is a large predator fish. It accumulates heavy metals like mercury.
- Small bodies, big risk: A human can handle a can of tuna. A 10lb cat eating that same can is ingesting a massive dose relative to body weight.
- Symptoms: Loss of coordination, blindness, and tremors.
2. Malnutrition (Vitamin E Deficiency)
Tuna is high in unsaturated fats but lacks Vitamin E.
- Steatitis (Yellow Fat Disease): If a cat eats primarily tuna, their body fat becomes inflamed and painful to the touch. It is a serious, painful condition.
3. Thiamine Deficiency
Raw fish contains thiaminase, an enzyme that destroys Vitamin B1 (Thiamine). Even canned cooked tuna lacks the full B-complex profile a cat needs.
"Tuna Junkies"
Cats can become addicted to the strong flavor of tuna. They may go on a "hunger strike" and refuse to eat regular cat food, holding out for the fish. This is a behavioral nightmare to fix.
Is ANY Tuna Safe?
Yes.
- As a Treat: A teaspoon once a week is fine.
- Cat Food Tuna: Use formulated cat food labeled "Tuna Feast". This has added Vitamin E, Thiamine, and Taurine to make it nutritionally complete.
Summary
Treat tuna like "cake" for cats. Tasty, but not a meal.