Yes cats can eat mackerel

Mackerel can help to ease constipation in cats and the rich levels of oils also benefit their coat and skin health. When giving mackerel, check where and how the fish was captured and give it in small moderation as a treat.

Cats should not be fed smoked or cured mackerel, due to its high salt content and additional ingredients such as seasoning and spices that can cause irritation to their digestive systems.

Fish cats can eat guide.