Mushrooms & Respiratory Failure

Although many wild mushrooms are harmless, others are potentially toxic. This retrospective case series evaluated 3 dogs with known mushroom ingestion (either witnessed or found following vomiting or gastric lavage) that developed respiratory arrest after presenting to the hospital with vomiting, tremors, and/or ataxia. None of the patients reportedly had access to any other toxin. IV diazepam was administered in 2 dogs, although it was unclear whether it had any clinical efficacy; these dogs recovered uneventfully after intensive supportive care, including manual or mechanical ventilation, IV fluids, and injectable medications. The third dog’s owners elected humane euthanasia because of clinical deterioration. Mushroom analysis was performed in only 1 case; however, neurologic or respiratory effects were not associated with mushrooms identified in this case. It was theorized that a previously unidentified or unknown compound or a mushroom type not recovered in the vomitus caused the clinical signs. One mushroom species, Amanita spp, is known to contain muscimol, a biologically active GABA analog. GABA stimulation causes respiratory arrest/apnea, and it is thought that a GABAergic compound was the underlying cause of severe clinical signs in these 3 dogs. 

Fungi are the most versatile, largest group of living organisms on earth. They can eliminate soil pollution, be used to treat infections, and produce insecticides. They can taste good, too, but they can impair and kill animals and humans. This article discusses a few things to consider when managing patients suspected of ingesting a poisonous fungus: 1) orogastric lavage may be helpful in recovering and identifying ingested mushrooms (in addition to decontamination); 2) benzodiazepines may contribute to respiratory failure; and, 3) respiratory failure may be reversible. It also reminded me how much more there is to discover in this world.—Elke Rudloff, DVM, DACVECC