Toxic Mushrooms and Your Dog

by Lisa McIntyre, DVM

As we know, summer and fall bring a unique set of seasonal scares for pet owning families. In addition to an increase in parasite exposure, wild animal encounters, and dog park injuries, exposure to certain environmental toxins also peaks.  Toxic ate in the warm, wet weather of season. Although they don’t do much to harm your lawn, be alert for signs of their growth as symptoms of toxicity can mimic other types of poisons and diagnosis can be challenging!

There are 4 classes of poisonous mushrooms; the classes are based on the type and severity of symptoms they cause. Additionally, mushrooms can be classified into groups, separated by the type of toxin they contain.  Poisonous varieties include false morels, hallucinogenic mushrooms, toamushroomdstool mushrooms, liver toxic mushrooms, and those that cause gastrointestinal signs or are muscarinic containing species.  Identification of the type your dog has consumed can be difficult once they pass your pet’s lips; treat any mushroom ingestion as a poisonous species and call your veterinarian immediately.   Another after-hours alternative is to call the National Animal Poison Control Center hotline at (888) 426-4435.  They are open 24/7 and 365 days a year and charge a nominal fee to advise you on how to manage your pet’s ingestion.   If a sample of the mushroom is available, consider contacting the North American Mycological Association ( to aid in identification.  1

The deadliest class of mushrooms are those that cause liver failure (hepatotoxic) with signs precipitating in 6-12 hours.  At this point, inducing vomiting with hydrogen peroxide or slowing toxin absorption with activated charcoal given orally is fruitless.  Once an animal has started to show signs of poisoning, it is no longer safe or advisable to try to expel the offending agent.  With names like “death cap” and “death angel”, liver cell death and eventual mortality can occur within a day or two, after being preempted by gastrointestinal upset. These mushrooms are found throughout North America including the Pacific Northwest, parts of California and the northeastern part of the United States. 2

Neurotoxic mushrooms affect the nervous system due to the compounds they contain and include psilocybin (“magic”), hydrazine and isoxazole mushrooms.  Magic or psychedelic mushrooms are often found indoors as part of a pet owner’s “pharmacy”.  Others grow throughout the United States but favor the West and Northeast.  2 Symptoms of ingestion are typically seen within 30-90 minutes, but effects can last hours longer. Varying from initial gastrointestinal upset to weakness, stupor, tremors, disorientation, vocalization and seizures, these mushrooms are typically less toxic but severity of illness depends on the amount ingested and the dog’s size and health status.

Gastrointestinal signs such as vomiting and diarrhea are seen early on after the ingestion of most mushrooms (15 minutes to less than 6 hours). Muscarinic containing mushrooms not only cause mild to severe vomiting and diarrhea, but ingestion can lead to dehydration, excessive salivation, tearing, urination, slow heart rate and difficulty breathing depending on the type and amount consumed. 3

Our last class of mushrooms, the nephrotoxic (kidney) varieties, are thankfully rare with poisoning reported in Europe.  Signs of toxicity are delayed by up to 8 days as the kidney cells are destroyed.  Symptoms of poisoning are typical of a dog in kidney failure and include vomiting, increased thirst, and urination; dogs can succumb if not treated aggressively with fluid therapy and hospitalization.

If caught within the first hours of ingestion, decontamination by inducing vomiting and delaying intestinal absorption, managing symptoms, and blood and urine sample monitoring are often successful at managing mushroom poisoning in dogs.  As always, be on the lookout in your yard for anything unusual underfoot!




Dog Poop and Disease



We fight a battle against hair shedding on a daily basis, our weapons of choice a Swifter and sticky rollers.  I also fight a weekly battle with my 12-year-old son to pick up the dog poop in the minefield that has become our backyard.  With two dogs, the mess is considerable.  “Why do I need to pick this UP?” he whines every Saturday morning.  I’ll give you the explanation I repeat to him… so that you can fight the good fight with your own tweens and teens.

Both humans and canines can acquire certain diseases from the waste of dogs.  In humans, diseases transmitted between species are known as zoonoses. Roundworms, hookworms, and whipworms are commonly known gastrointestinal parasites that are shed as eggs in dog feces. Human activities such as gardening, walking barefoot in the yard, or playing sports increase the risk of encountering those eggs and subsequent larvae.  Young children with less than stellar hygiene often go right from the sandbox to the lunchbox, where microscopic eggs can be consumed along with soil on the hands. Likewise, your dog, who by nature greets new playmates with a nose to rear acknowledgement, can acquire a new infection from a contaminated yard or surface. To spell it out plainly, dogs eat poop. Other protozoal parasites often found in dog waste are cryptosporidia and giardia.  These tiny organisms are easily transmitted between animals and people, causing signs of illness common to most parasitic infections: vomiting, diarrhea, weight loss, anorexia, poor haircoat, anemia and lethargy. In some cases, healthy adult animals and people exhibit no symptoms at all but can be actively shedding pathogens. Because humans are not the typical “host” for parasites such as roundworms, sometimes larval and adult worms take up residence outside of the gut.  Migration in tissues has caused disease in the lung, eye (which can lead to blindness), and skin. Besides direct hand to mouth transmission and direct skin contact with larvae, bacteria and parasites can be disseminated from a pile of fecal matter on lawn mower blades, the bottoms of shoes, after rainfall to areas of water run-off and nearby streams, and even on the bottoms of tiny fly feet.


What other diseases lurk in your dog’s poop? Salmonella, E. Coli, and Campylobacter are bacteria that are excreted in the feces of even healthy dogs. The Georgia-based Clean Water Campaign estimated that a single gram of dog waste can contain 23 million fecal coliform bacteria, which are known to cause cramps, diarrhea, intestinal illness, dehydration, and kidney disorders in humans. 1 You can do the math or trust mine; more than 70 million dogs in the United States alone produce over 10 million tons of poop each year. 2

Human and canine disease is not the only reason dog waste is harmful; feces in the water supply contributes nutrients that lead to overgrowth of harmful algae and weeds, killing fish and other wildlife. In fact, the Environmental Protection Agency lists dog poop as number three on its list of non-point sources of environmental contamination (meaning it comes from more than one source, millions of dogs!). 3

How can we address the problems caused by the more than 40% of pet owners who do not take pet waste removal seriously? 4 “It’s too much work, “it’s only in my yard”, “my dog isn’t sick” or “my dog is small” are common arguments against scooping poop.  Education is the first step to promoting a healthy environment. Many people erroneously believe that dog waste disappears into the dirt.  In fact, the 200,000 eggs laid by a single roundworm each day can persist for years without treatment from a concentrated bleach solution or flame thrower. 5 Start your pet on an oral or topical parasite preventative dispensed by your vet and insist upon bi-annual fecal screening.  A simple solution to promote safe poop disposal is to create a dog waste dump area near your garage consisting of a small lidded can and shovel and allowing neighbors to drop “deposits”.  Pet waste removal companies such as The Pet Butler take the olfactory assault of poop disposal off owners’ hands.  You can schedule a one-time clean up, or better yet, weekly cleanings to minimize yard contamination and disease transmission. The Pet Butler team disposes of dog poop in a timely and environmentally safe manner; no more excuses!