Canned Tuna (in excess)

Caution

Verdict

Occasionally OK — but not as a regular diet.

Toxic principle: mercury (chronic), nutritional imbalance
Source: ASPCA

Verdict

Small amounts of plain canned tuna in water (not oil) are safe for cats as an occasional treat. However, tuna is not a complete diet for cats — it lacks taurine, vitamin E, and other essential nutrients. Feeding tuna as a primary diet leads to nutritional deficiencies and mercury accumulation. Canned tuna also contains more sodium than cats need. Tuna addiction (cats refusing other food) is a real problem that develops from frequent tuna feeding.

Symptoms to watch for

  • none from occasional small amounts
  • mercury poisoning (chronic): hair loss, loss of coordination
  • steatitis (yellow fat disease) from vitamin E deficiency
  • nutritional deficiencies

What to do

Limit tuna to an occasional treat — a teaspoon or two, a few times per week at most. Always choose tuna in water with no added salt. Never use tuna as a primary cat food.

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Data sourced from ASPCA Animal Poison Control

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