✓ Reviewed against PDSA, Blue Cross & Animal PoisonLine guidance · Last reviewed: 2026-06
Can dogs eat button mushrooms?
The full picture
Button mushrooms (Agaricus bisporus) are the small white supermarket mushrooms. They're the same species as chestnut and portobello mushrooms — just harvested at different stages of maturity. All three are safe for dogs in small amounts, cooked plain.
Key points: cook them plain (no butter, garlic, onion); small amounts only (two or three small mushrooms for a medium dog); raw is harder to digest; old/slimy mushrooms harbour bacteria.
Nutritional value for dogs is modest — some B vitamins, selenium, and small amounts of vitamin D.
Risks to watch for
- Raw mushrooms harder to digest
- Often cooked with toxic seasonings (garlic, onion)
Potential benefits
- B vitamins, selenium, modest vitamin D
- Low calorie food topper
Safe portion size
Two or three small button mushrooms for a medium dog, plain cooked, once a week or so.
Safer alternatives
- Chestnut mushrooms (same species)
- Cooked carrot pieces
And while you're thinking about what's good for your dog, keeping on top of flea and parasite prevention is just as important as diet.