Can Cats Eat Mushrooms? Safe vs Toxic

Can cats eat mushrooms? A plain, cooked grocery-store mushroom — white button, cremini, portobello, even oyster — is non-toxic to a cat in a tiny amount. But the more useful answer is that cats are obligate carnivores: mushrooms aren’t a necessary or beneficial food for them. The real risks are what humans cook mushrooms with, and telling a store mushroom apart from a wild one.

Quick answer: Plain, cooked white button (and cremini, portobello, oyster) mushrooms are safe for cats as an occasional tiny taste — no garlic, onion, butter, oil, or salt. They aren’t toxic, but they’re not something a cat needs. Never feed wild mushrooms. If your cat ate a wild one, call your vet or the Pet Poison Helpline (1-855-764-7661).

For the full dogs-and-cats reference across every species, see the pet-safe mushrooms guide. For the dog side, see can dogs eat button mushrooms? and can dogs eat oyster mushrooms?

This is not veterinary advice. When in doubt, contact a vet or the Pet Poison Helpline. If your cat ate a wild mushroom, don’t wait for symptoms.

Cats are obligate carnivores — mushrooms aren’t a food they need

Unlike dogs, cats are obligate carnivores: their bodies are built to run on animal protein, and they get essential nutrients like taurine from meat, not plants. A mushroom isn’t poisonous to a cat, but it also doesn’t do anything for one. So the honest framing isn’t “should I add mushrooms to my cat’s diet” — it’s “my cat got into a mushroom, is that a problem?” Usually, with a plain store mushroom, no. With a wild one or a seasoned dish, potentially yes.

Why is my cat interested in mushrooms?

Cats can taste umami, and mushrooms are loaded with glutamate — the same savoury compound cats pick up in meat. That’s the likely reason a cat will sniff at or paw a mushroom: it reads as savoury. Curiosity isn’t a nutritional signal, though. A tiny plain taste won’t hurt, but there’s no reason to make it a habit.

If you offer a cat mushroom, do it this way

Two rules cover almost everything:

1. Cook it, plain, and keep it tiny. Steam or simmer in water for a few minutes. Cats lack the enzymes to break down chitin (mushroom cell-wall material) well, so raw mushroom commonly causes vomiting or loose stool. A taste — not a serving — is the right amount.
2. No seasoning, ever. Onion, garlic, leek, chive, and shallot (the Allium family) are toxic to cats and damage red blood cells, causing anemia — and cats are especially sensitive. Butter, cream, and oil add fat many cats can’t handle and can trigger stomach upset. A pan of garlic-butter mushrooms is dangerous to a cat because of the garlic and butter, not the mushroom.

Symptoms to watch for

Even with a plain, safe mushroom, watch for:

• Vomiting or diarrhea
• Drooling
• Loss of appetite or lethargy

These usually mean it was too much or simply didn’t agree with your cat, and they pass. Wild-mushroom symptoms are a different story — see below.

The real risk: wild mushrooms, not store mushrooms

A white button from the grocery store is one thing. A mushroom that sprang up in a potted plant or on the lawn is another entirely. Several species established in Canada — including Amanita phalloides (death cap), Amanita virosa (destroying angel), and Galerina marginata — can kill a cat from a tiny amount, and you cannot tell a safe wild mushroom from a deadly one by looking.

This is why MushroomGuide.ca is cultivation-only and does not publish wild-mushroom identification — see our foraging policy.

If your cat eats a wild mushroom:

1. Get it away from the cat and take a sample (including the base).
2. Photograph the mushroom and where it grew.
3. Call your vet or the Pet Poison Helpline (1-855-764-7661) immediately — don’t wait for symptoms.
4. Don’t induce vomiting unless instructed.

Bottom line

Plain, cooked store-bought mushrooms aren’t toxic to cats, but cats are obligate carnivores and don’t need them. If your cat steals a tiny taste of an unseasoned mushroom, it’s almost always fine. The two things that actually harm cats are the seasonings (especially garlic and onion) and wild mushrooms — never the plain mushroom itself.

This is not veterinary advice. Always check with your veterinarian before introducing new foods, especially if your cat has existing health conditions or takes medication.

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See also — cats, by mushroom: Can cats eat oyster mushrooms? — the oyster-specific answer. Can cats eat king oyster mushrooms? — the dense-stemmed “scallop” mushroom. Can cats eat button mushrooms? — white, cremini and portobello.

More: Pet-safe mushrooms guide — every cultivated species, for dogs and cats. Can dogs eat button mushrooms? — the dog side, with portion sizes. Foraging policy — why we don’t publish wild-mushroom identification.