Amanita muscaria toxicosis in two dogs


Address correspondence and reprint requests to:
Dr. John H. Rossmeisl, Jr., Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Mail Code 0442, Blacksburg, VA 24061.


Objective: To report the manifestations, history, and pathophysiologic basis of disease in 2 dogs with Amanita muscaria toxicosis.

Case summaries: Two dogs were evaluated for an acute onset of gastroenteritis and seizures. A. muscaria toxicosis was suspected in each dog after confirmation of environmental exposure and visualization of ingested mushrooms in vomitus. The diagnosis was confirmed following identification of toxic Amanita metabolites in the urine and serum of each dog. Administration of supportive and symptomatic therapies resulted in the complete recovery of each animal.

Unique information provided: Ingestion of the mushroom, A. muscaria, by dogs can result in acute gastrointestinal distress that precedes a potentially life-threatening central neurologic syndrome characterized by seizures, tremors, and somnolence. Central nervous system dysfunction results primarily from the actions of ibotenic acid and its decarboxylation product, muscimol, which are analogues of the neurotransmitters glutamate and γ-aminobutyric acid (GABA), respectively. Identification of these toxins in the urine and serum of affected dogs using high-performance liquid chromatography (HPLC) provides a definitive diagnosis.