Mushroom Poisoning in Dogs

If your dog has eaten a mushroom in your yard or while out on a walk, there’s a very broad range of symptoms he may experience - from no illness at all, to severe toxicity, to even death. In general, there are four categories of symptoms that mushroom poisoning may cause: gastrointestinal upset, liver disease, kidney disease, and neurologic disease.

Gastrointestinal Upset

The majority of poisonous mushrooms will cause stomach upset in dogs - vomiting and diarrhea. Symptoms can appear within 15-30 minutes or up to 12 hours. The most common variety to cause these signs is the muscarinic mushroom. There are many types of muscarinic mushrooms found across the US.

Liver Disease

Amanita phalloides, commonly known as ‘death caps’ or ‘death angels’ are a group of mushrooms known to be hepatotoxic (causing liver disease or failure). Signs of mushroom ingestion can be difficult to distinguish because most dogs initially have vomiting or diarrhea. However, within 6-12 hours, a poisoned dog may develop liver failure. Hepatotoxic mushrooms are common across the US, with the majority located in parts of California, the Pacific Northwest, and the Northeast United States.

Kidney Disease

Fortunately, nephrotoxic (causing kidney disease or failure) mushroom varieties are rare in the US. Cortinarius species are most common in Europe. Signs of poisoning are typically delayed by 12 hours, and up to 1 week, after ingestion. Affected dogs show signs of vomiting, dehydration, increased thirst, and increased urination.

Neurologic Disease

There are three types of neurotoxic mushrooms: isoxazoles, hydrazines, and psilocybin (“magic”) mushrooms. All three cause signs of toxicity quite rapidly, within 30-90 minutes of ingestion.

Neurotoxic mushrooms typically cause initial vomiting and diarrhea. Symptoms then move on to disorientation, vocalization, dizziness and staggering, tremors, and seizures. In cases of severe poisoning, the liver and kidneys may also be affected. Most cases of neurotoxic mushroom poisonings occur within the home when a curious dog finds his owner’s hallucinogenic mushrooms.

What can you do if you suspect your dog ate a poisonous mushroom?

If your dog has eaten a mushroom, it’s important to contact your vet right away. Because the onset of symptoms occurs quickly, your vet will want to start treatment as soon as possible. This will likely include making your dog vomit to remove as much of the mushroom as possible. Your dog may also need to be hospitalized for intravenous fluids and other supportive treatments. Blood work can be performed to monitor liver and kidney function.

Identification of the mushroom can be helpful. If possible, take pictures or bring the mushroom to your vet appointment. It’s important to note that collecting mushrooms or pictures should never delay treatment for your dog. Rapid decontamination and supportive care are a priority.

For more information about mushroom poisoning in dogs and mushroom identification, check out the ASPCA Animal Poison Control and North American Mycological Association websites.

Read more:

What foods are toxic to dogs?

7 Lesser-Known Foods That Are Toxic to Dogs

What plants are toxic to dogs?

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