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Can Cats Eat It?

Can Cats Eat Mackerel?

By Pettings · Sources checked Nov 2, 2026

Yes, in small amountsTreat size for a 10 lb adult cat: 1/3 ounce (10 grams) canned and drained or plain cooked, boneless (about 15 calories)

Cats can eat small amounts of plain cooked mackerel or drained canned mackerel. It is an oily fish with a strong smell that cats tend to like. As with any fish, mackerel works as an occasional treat on top of a complete cat food, not as a meal. The Merck Veterinary Manual links diets made largely of fish to yellow fat disease, a painful inflammation of body fat.

A pile of whole fresh mackerel
Photo: mehdi aydın on Pexels

What Mackerel Offers a Cat

Mackerel is animal protein and fish fat. Merck names oily fish as one of the best dietary sources of the omega-3 fats EPA and DHA, but a complete cat food already covers a cat's fat needs. The catch with oily fish is the same as its draw. Merck's cat owner guide says yellow fat disease is thought to come from a diet high in unsaturated fats and low in vitamin E. Mercury also varies by species. In FDA advice written for people, Atlantic mackerel is among the lowest-mercury fish, Spanish mackerel sits one step higher, and king mackerel is on the list to avoid. Merck notes that commercial fish products have caused long-term mercury poisoning in cats.

How Much Mackerel Can a Cat Have?

USDA lists canned jack mackerel, drained, at 44 calories per ounce. WSAVA advises keeping treats under 10% of daily calories, roughly 22 to 25 calories a day for a 10-pound adult cat. That puts a fair serving at about 1/3 ounce (10 grams), or about 15 calories. Subtract it from the day's regular food so the total stays the same. A whole fillet is several days' worth of treats. Ask your veterinarian before offering mackerel to a kitten, a senior, or a cat with diabetes, kidney disease, urinary stones, pancreatitis or a food allergy.

How to Serve It

For fresh mackerel, bake or poach it with no oil, salt, butter or seasoning, then pull the flesh away from the skin and bones. Canned mackerel is often packed in brine, oil or tomato sauce. Pick a can in water if you can find one, drain it well, and rinse off brine or oil. Leave sauced, smoked and salted mackerel for people, since the ASPCA warns that too much salt can cause vomiting, diarrhea and tremors. Check for bones carefully. Merck lists bones as the most common objects that get stuck in a cat's esophagus. Do not serve raw mackerel, as Merck lists raw fish diets as a cause of thiamine deficiency in cats.

If your cat has a medical condition or eats a special diet, check with your veterinarian before adding mackerel.

Common Questions

Can cats eat canned mackerel?

Yes, cats can have a small amount of canned mackerel if it is drained and free of sauce. USDA lists canned jack mackerel, drained, at 44 calories per ounce, so about 1/3 ounce is enough for a 10-pound cat. Choose fish packed in water when possible, and rinse off brine or oil. Skip mackerel in tomato or spicy sauces and pick out any bones.

Can cats eat smoked mackerel?

Smoked mackerel is not a good choice for cats. Smoked fish is usually heavily salted, and the ASPCA warns that too much salt can cause vomiting, diarrhea, tremors and even seizures in pets. Some smoked fish is also coated in pepper or other seasonings. Plain baked mackerel or drained canned mackerel with no added salt is a better way to share this fish.

Is king mackerel high in mercury for cats?

King mackerel is one of the highest-mercury fish, so do not share it with a cat. FDA advice written for people places king mackerel on its list of choices to avoid, while Atlantic mackerel is among the lowest in mercury. The Merck Veterinary Manual notes that commercial fish products have caused long-term mercury poisoning in cats, so lower-mercury species are the better pick.

Can cats eat raw mackerel?

Raw mackerel is not recommended for cats. The Merck Veterinary Manual lists raw fish diets, which contain the enzyme thiaminase, as a cause of thiamine deficiency in cats, a condition that affects the brain. Merck also notes that cooking destroys thiaminase. Raw fish can carry bacteria and parasites as well, so bake or poach mackerel plain before offering a small piece.

Can kittens eat mackerel?

A kitten can taste a small flake of plain cooked mackerel, but check with your veterinarian first. Kittens need a complete growth food, and WSAVA advises that treats stay under 10% of daily calories. Mackerel is rich and oily, so a very small amount is enough to see whether the kitten tolerates it. Remove every bone before offering it.

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