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My cat ate some cooked spinach that was left out on the counter overnight — could it make her sick?

Cats · Food safety

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

Short answer

It could. The spinach itself is safe when fresh, but after being left out, bacteria like Salmonella or E. coli can grow and cause food poisoning. Watch for signs like vomiting, diarrhoea, or lethargy in the next 6-12 hours. Make sure she has access to fresh water to stay hydrated. If she shows any of these symptoms, or if she seems off in any way, contact your vet for advice. For future treats, only offer fresh, properly stored vegetables in small amounts.

Spinach — Food safety facts

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

Small amounts are fine; large amounts of oxalates can be hard on the kidneys over time.

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

Spinach 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

A heavy salt load drives up thirst and urination, and in the worst cases leads to sodium ion poisoning, which is a genuine emergency.

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

Open the full food page: Spinach food facts →