Mushroom toxicity in dogs | Dr. Justine Lee

Posted by justinelee in Animal Safety, Blog, Pet Health

While there are thousands of species of mushrooms in North America, less than 100 are poisonous; these are most commonly of the Amanita species. Unfortunately, mushrooms are very difficulty to identify, and unless you are a mushroom expert/hunter or mycologist, then you should never eat a wild mushroom. Mushrooms sold in large-chain grocery store are safe and considered non-toxic to dogs.

There are 5 main types of mushrooms that are poisonous, and they all work by different ways.

• The most dangerous type of mushroom contains amanitin toxins, which results in severe gastrointestinal signs (within 6-24 hours), a “false recovery” period (where your dog appears to get better), and then severe liver failure (at 36-48 hours post-mushroom exposure). Kidney failure can also develop in the end stages. Examples of these types of deadly mushrooms include Amanita, Galerina, Lepiota, A. phalloids (death cap, death angel), and ocreata.
• Another type of mushroom contains muscarine and causes profuse SLUDGE signs (e.g., salivation, lacrimation, urination, diarrhea, gastrointestinal upset, emesis) and neurologic signs. They work somewhat similarly to the organophosphate and carbamates chemicals. Examples of these types of mushrooms include Inocybe spp. and Clitocybe dealbata.
• One type of mushroom contains muscimol and ibotenic acid, and causes profuse signs like ataxia, sedation and even tremors or seizures. Examples of these types of mushrooms include Amanita muscaria and pantherina.
• The false morel (Gyromitra spp.) causes profuse vomiting and diarrhea and is generally not fatal. Rarely, it can cause seizures.
• Some types of mushrooms just cause gastrointestinal irritation (e.g., vomiting, diarrhea) and are rarely life threatening when ingested. Signs can be seen in 1-6 hours, and generally resolve after 1-2 days. These types of mushrooms include the following types: Agaricus, Boletus, Entoloma
• Hallucinogenic mushrooms aren’t life-threatening and rarely need treatment. That said, signs of ataxia, acting abnormal, howling, nystagmus, and hyperthermia can be seen when dogs ingest them. These types of mushrooms include the following types: Psilocybe, Conocybe, Gymnopilus spp.

Volunteers at the National American Mycological Association (http://www.namyco.org/toxicology/index.html) may also help identify the mushroom for you (via image). If this is not readily available, all mushroom ingestions should be treated. As mushrooms are difficult to identify, treatment is based on “worst case scenario” (just in case it is Amanita spp.). As a result, treatment includes inducing vomiting (if appropriate), charcoal administration (to bind the poison from the stomach and intestines), anti-vomiting medication, and depending on what type of clinical signs are seen, anti-seizure medication, muscle relaxants, atropine and symptomatic supportive care.

If you think your dog ingested a mushroom, seek immediate veterinary attention – even in the middle of the night! The sooner you treat a mushroom poisoning, the better the prognosis for your dog and less expensive for you.

When in doubt, contact your veterinarian, emergency veterinarian, or ASPCA Animal Poison Control Center immediately for life-saving advice! Check out ASPCA’s free APP here too!