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Mushrooms: What do I do to treat my dog?



There’s a fungus among us: Mushrooms can be found wild, or purchased at the store!

With our Ms done today, we will be halfway through the alphabet!  When I started this, I wanted to do one post a day on a letter of the alphabet, but I underestimated how much time compiling these posts would take!  We may be down to one a week, but we’re still chugging along!  For Springtime, I wanted to include something your pets get outside – mushrooms.

When we talk about mushrooms, we have to distinguish what type of mushroom we’re discussing.  There is the edible form you put on your pizza, and then there are the wild mushrooms that grow in your yard in the spring and summer.

How toxic are mushrooms?

Grocery-store mushrooms are completely non-toxic to pets.  Like us, they have no problems with digesting the edible mushrooms we fix (unless of course they’re prepared with salts or other spices).  Even overeating this variety of mushrooms is more of a concern for tummy upset than it is anything else.

Wild mushrooms, on the other hand, come in several different types of toxins: non-toxic, ones causing more severe tummy upset, ones that contain muscarine, ones that cause central nervous system signs, ones that cause organ damage, and the extremely deadly ones.  How do you tell the difference?  At home, you most likely do not (unless you study mushrooms)!  There are so many different species of mushrooms that there is a field of study dedicated to it called “mycology”.

How can I tell which mushroom is involved?

While there are many online tools that may help in identifying what types of mushrooms you have growing in your yard, it can only narrow down the possibilities.  Sometimes the difference between a deadly mushroom and a non-toxic one comes down to minute differences unnoticeable by an untrained eye.  Luckily, there’s an organization called the North American Mycological Assocation (NAMYCO).  They are an organization comprised of mycologists, and they have volunteered to be on-call in poison emergencies if a mushroom needs to be identified in a hurry.  You can find a list of mycologists in your state and contact them by email with pictures (or even better – samples should you have the time).  They will work with your vet or poison control to ID the mushroom so your vet knows how to treat them.

BE CAREFUL when attempting to have a mushroom identified. Mushrooms grow in clusters, and while they often LOOK similar, the clusters may have several different species growing together.  Your pet could eat the cap off of one mushroom that is practically attached to another mushroom of another species.  BE SURE to grab the mushroom that is partially ingested if possible.  Should your pet eat the entire thing, you can try to identify the surrounding fungi, but beware that more preventative treatments may be necessary since you cannot be 100% sure of the species.

Signs caused by mushrooms

The signs of a mushroom ingestion are going to vary based on mushroom type.  Once identified, the vet will be able to determine what signs are to be expected and what needs to be done in the way of treatment. Non-toxic mushrooms may cause a little bit of vomiting and diarrhea, but are usually treatable at home.

Mushrooms that cause stomach upset

These guys are similar to the non-toxic mushrooms in the way that they can cause vomiting and diarrhea.  However signs tend to be more severe as well as causing some additional side-effects:

  • Vomiting
  • Diarrhea
  • Tummy pain
  • Lethargy
  • Weakness
  • Disorientation

In many cases, the specific chemical causing toxicity is unidentified in these guys, but in most cases, these do not lead to death.

Muscarine mushrooms

Several species of mushroom contain muscarine, which is a type of chemical that can cause some concerning signs in pets:

  • Excess drooling
  • Excess production of tears
  • Vomiting
  • Urination
  • Diarrhea
  • Constricted pupils (tiny pupil size)
  • Fast heart rate
  • Decreases in blood pressure
  • Difficulty breathing

As scary as these signs are,  there is an antidote available through your vet.  Because of this fact, these types of mushrooms rarely cause death.

Nervous system mushrooms

Signs affecting the brain and nerves can be caused through stimulation or depression of the nervous system, or through the altering of behavior due to hallucinations (“shrooms” being a more common mainstream name for hallucinogenic mushrooms).  These can cause a wide variety of behavioral changes or neurological problems:

  • Agitation or anxiety
  • Aggression
  • Depression
  • Sleepiness or coma
  • Vomiting
  • Crying
  • Stumbling (ataxia)
  • Difficulty breathing
  • Hyperactivity
  • Increases or decreases in heart rate
  • Over-reactive reflexes
  • Drooling
  • Tiny pupils or dilated pupils
  • Diarrhea
  • Decreases in blood pressure
  • Heart arrhythmias
  • Tremors
  • Seizures

Again, despite the scary signs, they can all be managed well at a vet clinic, though there is no specific antidote for them.  If care is sought quickly, pets who ingest these types of mushrooms tend to do well, and death is not common.

Mushrooms that cause organ damage

Now we start to get into the mushrooms that CAN be pretty lethal.  In addition to tummy signs, these mushrooms can cause damage to the liver and kidneys:

  • Vomiting
  • Liquidy diarrhea
  • Tummy pain
  • Lethargy
  • Fever
  • Liver and kidney damage
  • Destruction of red blood cells
  • Inadequate release of oxygen to tissues
  • Decreased blood sugar
  • Seizures

These mushrooms can cause death.  There are a lot of factors that determine if a pet survives, so immediate care is imperative.  Signs come in phases:

  • Tummy signs – between 12-24 hours after eating one
  • Severe tummy signs – Between 18-24 hours after eating one
  • Everything appears normal – there can be a short bit of time up to 48 hours after ingestion where they can appear to have recovered
  • Life-threatening – this is when organ damage and all of the other severe signs occur – usually about 36-84 hours after exposure.  Prior to this state, animals may possibly treated to prevent further signs, but it becomes far less likely that they will survive if these signs start to occur.

Extremely deadly mushrooms

Technically, these mushroom species belong in the above category, but three genus in particular cause irreversible damage and extremely severe signs in very small amounts:


Aminata (Death Cap) – These look nearly identical to forms of edible mushrooms.  Because of this, it is the most common mushroom involved with human poisonings from people who pick wild mushrooms to eat. As little a 1 milligram is enough to kill a large dog.  Oddly enough, rodents and rabbits do not seem to be affected  by these! These are most common in Europe, though it may exist on the west coast of North America.


Galerina – This is a mushroom that is often mistaken for a hallucinogenic mushroom.  People seeking recreational activities might pick this instead due to its similar appearance. There is a debate on whether it is more or less toxic than the above, but it contains the same type of chemical.  It is also found in North America and several other countries.


Lepiota – Many different species in this genus have varying patterns, though they all tend to be umbrella-shaped white mushrooms with brown accents.  While not all of the species are poisonous, the ones that are poisonous are of the deadly variety.  These are also common in Europe, though they tend to be found in warmer climates rather than colder ones. There are 400 different species that have been identified all over the world.


Treatments for all types of mushrooms is too varied to compile into a list.  Many vets will have an owner induce vomiting immediately at home if it is safe to do so.  For an owner, the most important thing to do in a situation where a pet has ingested a mushroom is to take pictures and collect samples.  Use gloves, since touching some mushrooms can be problematic for humans as well, then contact NAMYCO for identification.


If you find mushrooms growing wild in your yard, don some gloves and pull them out for proper disposal (not the indoor trashcan).

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