Fatal canine metaldehyde poisoning in Southern Brazil

Abstract

Metaldehyde is commonly used as a molluscicide, and accidental ingestion in dogs is a recognized toxicologic emergency with potentially fatal outcomes. A 4-month-old female Pit Bull was presented to a veterinary emergency after ingesting an unknown amount of a 5% metaldehyde-based slug bait (Metarex®). Clinical signs began within minutes and included stupor, hypersalivation, and generalized tonic-clonic seizures. Supportive care was provided, including anesthetic coma with propofol and isoflurane, gastric lavage, diazepam, N-acetylcysteine, and oxygen therapy; however, the animal died in eight hours. At necropsy, the stomach and intestines contained abundant blue-to-green amorphous and finely granular material, as well as plastic fragments consistent with Metarex® packaging. No significant microscopic alterations were observed in internal organs. The diagnosis was based on the clinical course, history of exposure, and characteristic gastrointestinal contents. In suspected cases, identification of metaldehyde in the gastrointestinal tract can aid diagnosis when toxicologic confirmation is unavailable.