My 5 kg cat ate three mussels that had been sitting out on the counter all night — should I take

Short answer

Yes, this is worth a vet visit. Cooked mussel meat itself is safe for cats, but once it has been left out overnight it can harbour harmful bacteria such as Vibrio and Salmonella. A 5 kg cat is small enough that even mild bacterial contamination can produce significant vomiting, diarrhoea or lethargy within a few hours. Call your vet to describe what happened and ask whether you should come in, or go directly if she is already showing signs of illness.

Mussels — Food safety facts

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

Cooked and removed from the shell, in small amounts. Raw shellfish carries bacteria.

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

Mussels 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

Raw animal protein carries Salmonella and E. coli risk, and those bacteria can spread to the people in the household too.

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

Open the full food page: Mussels food facts →

My 5 kg cat ate three mussels that had been sitting out on the counter all night — should I take her to a vet?

Mussels — Food safety facts

Why these cautions matter

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