Throughout the spring, summer, and fall there are many types of mushrooms that naturally grow in backyards.  Although many mushrooms are harmless, there are certain varieties that can poison your pet.  Here, mushrooms that are dangerous to your dog will be discussed as well as what to do if your dog ingests a poisonous mushroom. Dangerous Yard Mushrooms There are four types of dangerous mushrooms.  Category A mushrooms are most toxic and destroy kidney and liver cells.  Category B and C mushrooms affect the nervous system and can cause symptoms such as hallucinations.  Category D mushrooms cause gastrointestinal distress, such as vomiting and diarrhea.  Regardless of the type of mushroom your dog consumes, the most likely symptoms include: Vomiting Diarrhea Abdominal pain Disorientation Lethargy Weakness Jaundice Lack of coordination Excessive drooling Seizures Coma Fly Agaric (Amanita Muscaria) The Fly Agaric is common in wooded areas throughout North America.  This mushroom...