Why?
Mackerel is an oily fish, rich in protein and omega-3s, but also high in calories: too often, it can cause weight gain and diarrhea. It's mostly sold smoked, salted or canned in tomato, mustard or wine sauces, which are too salty or seasoned for a cat. Raw mackerel can carry parasites such as Anisakis. Atlantic mackerel is low in mercury, but king mackerel is high, so skip that one.
How much?
A small bite of mackerel, steamed or baked with no salt and no bones, about once a week. If canned, choose mackerel packed in water with no added salt, and drain it.
The risks
- Mackerel in sauce: salt, wine, spices, sometimes onion
- Smoked mackerel, very salty
- Diarrhea and weight gain if fed often
- Bones in fresh fish
- Raw mackerel: parasites like Anisakis
Your cat ate some: what now?
A small amount, even in sauce, usually isn't serious: watch for 24 to 48 hours. Call your vet for repeated vomiting, heavy diarrhea, extreme thirst or lethargy, or if your cat ate a whole can.
Better options
Half a sardine packed in water with no added salt, or a bit of plain cooked salmon, is easier to find in a cat-friendly form.
Common questions
Can cats eat smoked mackerel?
No, it's far too salty. Offer a small piece of plain cooked fresh mackerel instead.
Can cats eat canned mackerel?
Yes, occasionally, if it's packed in water with no added salt, drained and given in a small amount. Skip mackerel in oil, tomato sauce or mustard.
This information is general and does not replace advice from a veterinarian. If your cat has swallowed something toxic, call your vet or an animal poison control center right away, without waiting for symptoms.