Can dogs have wild mushrooms?
No – wild mushrooms can be extremely dangerous for dogs. Treat any outdoor mushroom ingestion as an emergency.
Why it is or is not safe
Many wild mushrooms contain toxins that can damage the liver, kidneys, nervous system, or cause life-threatening gastrointestinal illness. Correct identification is difficult, and delays can be dangerous.
How to serve
Call your vet or an emergency clinic immediately. If possible, bring a sample of the mushroom or a clear photo to help identification. Do not wait for symptoms.
Symptoms to watch for
Drooling, vomiting, diarrhea, weakness, tremors, seizures, jaundice, collapse.
Sources: See full veterinary references here