Suspected Japanese Pieris (Pieris japonica) Poisoning in an Alpaca (Vicugna pacos)

A zoo-housed alpaca was found recumbent with profuse frothy salivation and an inability to stand. Supportive treatment, including intravenous fluid therapy via the jugular vein and oral administration of activated charcoal, was initiated. Despite these interventions, the animal’s condition progressively worsened, with clinical signs including vomiting and neurological manifestations such as paddling movements and opisthotonus. The alpaca died approximately 4 h after discovery by first observation of clinical signs. Necropsy revealed a large volume of white, foamy fluid present in the tracheal and bronchial lumens. The lungs were dark red and markedly congested and edematous throughout all lobes. Multiple ecchymotic hemorrhages were observed on the mucosal surface of the pyloric region of the third compartment of the stomach and on the serosal surface of the duodenum. Histopathological examination revealed severe pulmonary congestion and edema, along with marked congestion of the liver, spleen, and kidneys. The gastric contents were green and contained plant material, including ten leaves morphologically identified as Japanese pieris (Pieris japonica). Postmortem inspection of the enclosure revealed the presence of Japanese pieris shrubs with evidence of browsing. Based on these findings, acute poisoning from ingestion of Japanese pieris was diagnosed.