MUSHROOM ALERT! We have noted numerous mushrooms around our property over the past 24 hours. Please check your yards and pastures carefully. Mushrooms can be highly toxic and even fatal for dogs, cats, and horses, although dogs are the mo...st commonly poisoned. Symptoms of mushroom toxicity can be quite variable depending on the type of mushroom, but can include vomiting, diarrhea, lack of appetite, lethargy, tremors, seizures, etc. If you think that your animal may have been exposed to mushrooms, consult your veterinarian right away.