Ask the Vet: Toxic Mushrooms Resemble Harmless Varieties
Q: We've had a lot of rain this year, and our yard is filled with a variety of mushrooms. How can we identify those that could poison our dogs, and how will we know if our dogs ate them?
A: Animal poison control specialists are receiving twice as many calls about mushroom poisoning this year as last. That's frightening because toxic mushrooms grow throughout the U.S. during all seasons of the year, popping up quickly in moist areas.
Toxic mushrooms look a lot like nontoxic mushrooms. Even scarier, one or two toxic mushrooms may grow in a group of harmless mushrooms or beneath your mulch.
Only an expert can differentiate a toxic mushroom from one that's harmless. So, assume the mushrooms growing in your yard are toxic unless an expert tells you otherwise.
Some mushroom species are so toxic that ingestion of only a tiny amount is deadly. For example, half a death cap mushroom can kill an adult human.
So, it's best to remove all mushrooms from your yard. Put them in a plastic bag; dispose of the bag in your trash; and wash your hands.
If one of your dogs eats a toxic mushroom, he'll develop clinical signs that reflect the mushroom species and involve one or more of the following body systems:
-- Brain. Dogs quickly become weak, disoriented, uncoordinated and agitated. They may vocalize and develop tremors and seizures. "Magic mushrooms" contain psilocybin, which causes hallucinations in humans and seems to do the same in dogs.
-- Stomach/intestines/liver. Mild to severe abdominal pain, vomiting and diarrhea may develop within 15 minutes or be delayed up to 12 hours. Depending on the species, the mushroom may slow the dog's heart or damage his liver. The death cap mushroom, found throughout the U.S., causes liver failure and death within two days of ingestion.
-- Kidneys. Mushrooms that damage the kidneys cause vomiting and increased drinking and urination within a week of ingestion.