Not all mushrooms are edible, and certain ones can be deadly. Of particular concern are those in the Amanita genus. Here are some resources to help you identify dangerous mushrooms that would be harmful to your dog or cat.
If you fear your dog or cat has eaten a poisonous mushroom seek veterinary help immediately. They can go into a coma-like sleep within hours of ingestion or suffer severe liver failure. Time is truly of the essence. Contact your veterinarian, a pet poison control center or visit your local Animal ER.
Resources
State-by-state list of mushroom experts who can help you with mushroom identification in poisoning cases
With names referencing death and destruction, it’s no wonder the Amanita mushroom genus contains some of the most famous and deadly of all poisonous mushrooms. The death cap (Amanita phalloides) is suspected to have caused more mushroom poisoning deaths than any other species!
Yet what makes some amanita mushrooms so poisonous? Certain species of Amanita contain amanitin, a deadly amatoxin.
Amatoxins are some of the most lethal poisons found in nature. These toxins work by slowly shutting down the liver and kidneys. Often the victim will appear sick at first, and then seem to get better. Unfortunately the amatoxins are still at work, and death may occur anywhere from a few days to a week after ingestion.
This poison knows no real antidote beyond treating the victim with an extract of milk thistle. Milk thistle protects against liver damage from toxins, and is one of the treatments for amanita mushroom poisoning.
Remember: Never solely identify any mushroom based on what you’ve seen on any website (including this one) or by comparing it to a picture in a book. Always obtain hands-on expert help when identifying a new mushroom and never eat anything you’re not sure of!
Death Cap Details
Cap
Convex initially but flattens with age, often sticky when touched
Between 3 to 6 inches across
Color is usually a shade of yellow to green, but sometimes white or brownish
White gills underneath the cap that don’t run down the stem
Stem
Between 3 to 6 inches across and less than an inch thick
Usually whitish, sometimes with scales
Often a ring around the stem right below the cap. This ring is the remnant of the partial veil, a piece of tissue that protected the mushroom’s gills as it grew.
Also present is a white sac around the base of the stem. All amanita mushrooms start their lives as small buttons in the shape of an egg. This egg-like covering is actually a layer of tissue called the universal veil, or volva.
Because they form as a small button, an amanita may sometimes be mistaken for an edible puffball. This is why it’s essential to slice a puffball open before eating it. Puffballs are white and solid on the inside with no gills. If you see gills, you may have an amanita on your hands.
Once the mushroom has grown, the sac-like remnants of this universal veil are still an important identification characteristic. It’s often underground so you may have to dig carefully around the base to find it.
However, never assume that you don’t have an amanita mushroom just because you can’t find the sac. It may have disintegrated or broken away. Use all features for poisonous mushroom identification, not just one!
Amanita phalloides, the death cap mushroom The mushrooms have a sweet odor (like honey) and are attractive to some dogs (whose owners report they actually seek them out to eat them). They are really non little white mushrooms. The toxic effects appear about 6-36 hours after the mushrooms are eaten, and once signs are seen the toxicity is poorly responsive to treatment (we try a lot of things to support the animal, but if enough mushrooms were eaten it will be fatal despite the treatment). If someone suspects their dog may have eaten a mushroom, the best treatment is to take the dog immediately to a vet or emergency clinic and have them induce vomiting and give activated charcoal. The mushroom toxin is absorbed fairly rapidly, but the damage to the liver can take hours before it is clinically apparent. Don’t waste time trying to figure out if the mushroom is toxic as speed in removing the mushroom from the digestive system is the most important thing in my experience.Here is a link with some pictures https://wikipedia.org/wiki/amanita_phalloides
Although most SF/local mushrooms are not poisonous, and those that are usually cause only digestive upset (perhaps causing someone to wish they would die), Death Caps (Amanita phalloides) are aptly named. After an initial digestive upset death caps prevent liver cells from regenerating. Within a few days after ingestion there are no new liver cells to replace the old ones, and liver failure occurs. The below message describes death caps as “little white mushrooms.” Note: They might look like that in the early stages, but mature mushrooms can grow quite large (check yahoo group for photo of mushroom I’m holding in hand) and they have a slight metallic, greenish look. Check out the wikipedia link for photos of death caps in various stages. I have seen death caps south of SF and in the east bay. There might be some in SF. The common “white mushrooms” I’ve seen in SF, e.g. growing in lawns, are not death caps (various Agaricus–see photo). Death Caps have WHITE GILLS (e.g. the radiating blades on the underside of the cap), while most of the “lawn” mushroom have brown gills. At Fort Funston beneath the trees, I’ve spotted white-gilled mushrooms, but they have shaggy scales on the cap (see photo). Not death caps. Possibly Lepiota rachodes. Don’t take a chance w/mushroom, especially death caps. Supervise your dog.
Other Infamous Amanita
No page on poisonous mushrooms would be complete without discussing the death cap’s deadly cousin, the destroying angel.
The term “destroying angel” actually refers to a few all-white poisonous mushrooms in the Amanita genus. They are:
Amanita bisporigera in Eastern North America
Amanita ocreata in Western North America
Amanita virosa in Europe (below)
Amanita virosa is known as the “European destroying angel”. There is some disagreement as to whether this mushroom exists in the United States.
Destroying angels are sometimes mistaken for edible mushrooms such as young puffballs, button mushrooms, and meadow mushrooms. Thus it’s important to learn how to identify them.
The destroying angel is very similar to the death cap in terms of identification. The biggest difference is that they’re all white, with no green or yellow tint. They’re recognized by their rounded base, white color, and smooth cap. One bite of these may contain enough amatoxins to kill!
Of course, not every species in the Amanitamushroom genus is poisonous. Some, such as Amanita caesarea (Caesar’s mushroom), are edible. Yet given the danger involved in eating the wrong amanita, it’s best to avoid the genus entirely unless you really know what you’re doing.
It’s important to learn how to recognize Amanitas (especially the death cap and the destroying angel) if one is going to start eating wild mushrooms. Proper knowledge can prevent a fatal mistake!
– See more at: https://www.mushroom-appreciation.com/death-cap.html#sthash.aPp52tla.dpuf
