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How can I stop my curious 6 kg cat from stealing oily mackerel off the kitchen counter?

Cats · Food safety

Last reviewed: 2026-09-05 · Reference ranges: ASPCA, Pet Poison Helpline & Merck Veterinary Manual

Short answer

Always store mackerel and other fish in sealed containers in the fridge or a closed cupboard immediately after use. Never leave it unattended on the counter. You can also train a strong 'leave it' command using high-value cat treats as a reward for ignoring the fish. Consistency is key—every time your cat shows interest, redirect her to a toy or her own food. While cooked mackerel is safe in tiny amounts, preventing access is the best way to avoid any potential stomach upset from the rich oils.

Mackerel — Food safety facts

Safe to share · Cats · full breakdown on the linked food page

Safe cooked, but it is oily — small occasional portions only.

Dogs and cats carry the same rating (Safe to share), so the notes below hold for either pet.

Mackerel is not toxic to cats. The real limit is calories, fat and salt, so treat it as a small extra alongside the normal ration rather than a meal in itself.

There is no poisoning risk here, and the usual problem is simply eating too much at once: a heavy fat or salt load can bring on loose stools or a single vomit. Offer water, keep an eye on the pet for 24 hours, and do not induce vomiting.

Why these cautions matter

Rich, fatty food is the classic trigger for pancreatitis, a painful inflammation of the pancreas that usually needs veterinary treatment rather than rest alone.

The full verdict, portion guidance and serving notes are collected on the Mackerel food facts page.

Open the full food page: Mackerel food facts →