Can Cats Eat Mackerel?

⚠️ In Moderation

✅ Cross-checked against veterinary poison-control guidance · Oct 2026 audit

⚠️ Educational info only. If your pet just ate something and looks unwell, skip the reading and call your vet or Pet Poison Helpline (US): (855) 764-7661.

Occasional plain cooked mackerel is fine, but choose the right species and never raw.

Why it’s a sometimes-food

Atlantic mackerel is a low-mercury oily fish rich in omega-3s, while king mackerel is a large, long-lived species with high mercury and is best avoided. Like many raw fish, mackerel contains thiaminase, an enzyme that destroys vitamin B1, so cooking is not optional.

How to serve it safely

Offer a small piece of plain cooked Atlantic mackerel once a week at most, with every bone removed.

Warning signs to watch for

Regular raw mackerel feeding leads to thiamine deficiency — vomiting, appetite loss, a bent-down neck posture and seizures.

When to call the vet

See a vet promptly if a cat that eats raw fish develops neurological signs — thiamine deficiency is treatable when caught.

Common questions

Is canned mackerel okay?

Only if packed in water with low or no added salt, and drained. Oil-packed or salted versions undo the benefit.

More foods for cats

Salmon✅ SafeYes, when fully cooked and unseasoned. Salmon is a nutritious fish most cats enjoy.Tuna⚠️ In ModerationOccasional small amounts only — tuna should be a treat, never a meal.Cow’s Milk🚫 Not RecommendedBetter to skip it. Most adult cats are lactose intolerant and milk gives them stomach upset.Garlic☠️ ToxicNo. Garlic is poisonous to cats — even more potent per gram than onion.Cooked Eggs✅ SafeYes, fully cooked and plain. Eggs are a protein-rich treat cats usually enjoy.Cheese⚠️ In ModerationSmall bites are usually fine, but many cats cannot digest dairy well.

This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate something concerning, contact your veterinarian or a pet poison hotline right away.