Laurie Anne Walden, DVM
Most wild mushrooms aren’t dangerous, but some are fatal if eaten. Keep your pets safe by removing wild mushrooms from their environment.
Because it’s not easy to know if a wild mushroom is poisonous, treat any wild mushroom ingestion as a medical emergency. If your dog or cat eats wild mushrooms, call an emergency animal clinic, your veterinary clinic, or a pet poison hotline right away. Don’t wait until your pet gets sick before you call. Some of the most toxic mushrooms don’t cause symptoms until hours after they’re swallowed.
Pet poison hotlines (fees might apply):
ASPCA Animal Poison Control: 888-426-4435
Pet Poison Helpline: 855-764-7661
Photos of toxic mushrooms in North Carolina:
NC State Extension Gardener Plant Toolbox: mushrooms
Symptoms of mushroom poisoning depend on the type of mushroom and the amount eaten. Toxic mushrooms can be categorized by the type of problem they cause: liver and kidney failure, central nervous system effects, muscarinic reactions, hallucinations, or gastrointestinal irritation.
Liver and Kidney Failure
The mushrooms responsible for the most deaths are in the Amanita, Galerina, and Lepiota genera. Examples are Amanita phalloides (death cap), Amanita bisporigera (destroying angel), and Galerina autumnalis (autumn skullcap).
The toxic compounds in these mushrooms are amatoxins, phallotoxins, or virotoxins. These toxins damage cells of the liver, kidneys, and intestines. The symptoms progress through stages:
Central Nervous System Effects
Mushrooms containing the compounds ibotenic acid and muscimol affect the central nervous system. The mushrooms most often involved in this type of poisoning are Amanita muscaria (fly agaric) and Amanita pantherina. Symptoms usually begin 30 minutes to 2 hours after ingestion (possibly earlier in cats) and include the following:
Muscarine is a substance that affects a specific metabolic pathway in cells of the body. Ingestion of muscarine-containing mushrooms—usually Clitocybe and Inocybe species—causes clinical signs related to part of the nervous system that regulates routine (not conscious) body functions. Symptoms appear a few minutes to a couple of hours after ingestion:
Hallucinogenic mushrooms include those in the genera Psilocybe, Conocybe, Panaeolus, Copelandia, Pluteus, and Gymnopilus. The toxic components are psilocybin and psilocin, which are similar to the drug lysergic acid diethylamide (LSD). Symptoms usually begin within an hour or two after ingestion:
Many mushrooms cause gastrointestinal (digestive tract) problems. The exact toxin in most of these mushrooms is not known. Some of the mushroom genera that cause this type of problem are Chlorophyllum (which often forms fairy rings on lawns), Omphalotus, and Scleroderma. Symptoms usually begin soon after ingestion and improve on their own within a few hours. Most symptoms are mild:
Diagnosing mushroom poisoning is difficult unless the animal is seen eating the mushroom or vomits up pieces of mushroom. Known access to wild mushrooms, compatible symptoms, and physical examination findings can put mushroom poisoning on the list of possibilities. Blood and urine tests are used to assess organ function in dogs with symptoms.
Treatment depends on the symptoms and type of mushroom (if known). Animals exposed to the most toxic mushrooms need early and aggressive treatment to survive. Unfortunately, early treatment isn’t possible if the ingestion was not witnessed and symptoms don’t begin until several hours later.
No antidote is available for mushroom poisoning. The best way to manage the risk is to prevent pets from eating wild mushrooms.
1. Hovda LR. Unfriendly fungi: five groups of mushrooms toxic to pets. DVM 360. Published October 20, 2015. Accessed July 23, 2020. https://www.dvm360.com/view/unfriendly-fungi-five-types-mushrooms-toxic-pets
2. Brownie CF. Poisonous mushrooms. Merck Veterinary Manual. Updated August 2014. Accessed July 23, 2020. https://www.merckvetmanual.com/toxicology/poisonous-mushrooms
3. Cope RB. Toxicology brief: mushroom poisoning in dogs. DVM 360. Published February 1, 2007. Accessed July 23, 2020. https://www.dvm360.com/view/toxicology-brief-mushroom-poisoning-dogs
Photo of Galerina species by Bernard Spragg
Laurie Anne Walden, DVM
The contents of this blog are for information only and should not substitute for advice from a veterinarian who has examined the animal. All blog content is copyrighted by Mallard Creek Animal Hospital and may not be copied, reproduced, transmitted, or distributed without permission.