Remember the adage: “There are old mushroom hunters, there are bold mushroom hunters, but there are no old, bold mushroom hunters.” All wild growing mushrooms should be considered toxic until proven otherwise. Ideally samples of ingested mushrooms should be brought to the clinic with your pet. Don’t place the mushroom in a plastic bag; instead wrap them in a moist paper towel. Identifying mushrooms is very complex, and your Veterinarian will have to consult Poison Control or a Mycologist.
The most common species associated with fatal mushroom poisoning in dogs and people is Amanita phalloides: the death cap mushroom. The toxic cyclopeptides (alpha amanitin) in these mushrooms initially causes severe gastrointestinal signs and leads to kidney and liver failure within three days. Early aggressive treatment is essential, and even with treatment prognosis is grave.
Amanita pantherina, a psychoactive mushroom, is one of the most common causes of mushroom poisoning in the Pacific Northwest. Its preferred habitat is under conifers, pine, oak and especially Douglas-fir. The toxic compounds associated with this mushroom is ibotenic acid and muscimol, which are psychoactive. In people these are reported to alter visual perceptions. Ibotenic acid is a stimulant and muscimol is a depressant/sedative, therefore, the symptoms alter between periods of hyperactivity and depression, even comas. There is no antidote, although with extensive supportive treatment most patients can survive.