Amitraz toxicosis in 3 dogs after being in a rice field

To describe the clinical course and novel biochemical findings in 3 dogs with amitraz toxicosis.

Three Labrador Retrievers developed acute onset obtundation to stupor after being in a rice field. On admittance to the hospital, they all displayed bradycardia, hyperglycemia, hyperlactatemia, respiratory acidosis, and metabolic alkalosis. All clinical signs resolved in 18-48 hours with supportive care. One dog represented with similar clinical signs and biochemical abnormalities 3 days after discharge following spending time in a different rice field owned by the same owner. Toxicological analysis of serum from all 3 dogs and vomitus from 1 dog returned positive for amitraz and one of its metabolites.

This is the first case series of dogs with confirmed amitraz toxicosis following an environmental exposure. Novel biochemical findings of hyperlactatemia, respiratory acidosis, and metabolic alkalosis were documented in all 3 dogs. Clinicians should be concerned for amitraz toxicosis when presented with an animal with the constellation of signs including decreased mental status, bradycardia, and hyperglycemia, particularly if relevant acid-base abnormalities are also detected.