Mackerel: Safe for Dogs and Cats?

Some mackerel species can be offered fully cooked and plain, but king mackerel should be avoided because of mercury, and raw fish, bones, salt, oil, and seasoning add separate risks.

Plain cooked mackerel can be an occasional cat treat, but king mackerel should be avoided because of mercury and raw, smoked, salted, oil-packed, or seasoned forms change the answer.