Quantity
With the most toxic species like death caps, even a small amount — a single mushroom cap — can be enough to cause fatal liver failure. With less toxic species, larger quantities cause gastrointestinal illness. Because identification in the field is nearly impossible, treat all wild mushroom ingestion as potentially serious.
Notes
Mushrooms fruit prolifically after rain, especially in autumn and spring. They can appear overnight in a paddock that was clear yesterday. Horse manure is actually an excellent substrate for some mushroom species, so paddocks that aren't regularly cleaned can develop their own mushroom crops. Most pasture mushrooms are harmless, but the occasional toxic species can appear without warning.
Negative Signs
* Colic — pawing, rolling, looking at flanks
* Diarrhea, sometimes bloody or watery
* Loss of appetite and depression
* Jaundice — yellowing of gums and eyes (liver damage)
* Staggering and loss of coordination (neurological species)
* Excessive salivation and drooling
* Photosensitization — sunburn-like skin reactions on light areas (liver damage)
FAQ
Q: Mushrooms keep growing in my horse's paddock after every rain. Should I remove them all?
A: Yes. You probably can't identify every species growing in your field, and one toxic mushroom is all it takes. Walk the paddock after rain, pull up any mushrooms, and dispose of them. Reducing manure buildup also helps limit mushroom growth.
Alternatives
Walk your paddocks regularly, especially after rain. Remove any mushrooms you find by pulling them up (wearing gloves) and disposing of them in sealed bags. Keeping paddocks clean of manure piles reduces the substrate available for mushroom growth.
Risks & Disclaimer
If you notice your horse eating wild mushrooms or see mushrooms in a recently grazed paddock and your horse shows any signs of illness, call your vet. Try to collect a sample of the mushroom (with gloves) or take clear photos from multiple angles for identification.
