Abstract
Six dogs died after accidental ingestion of cottonseed bedding. No clinical signs of illness were observed prior to death. A full diagnostic workup was performed on one of these dogs. At necropsy, the lungs were congested and edematous, and the liver was firm, congested, and had a marked reticular pattern. There was also moderate ascites. Histopathologic examination revealed multifocal myocardial degeneration and necrosis, severe pulmonary edema, and chronic passive congestion of the lungs, heart, liver, and kidneys. Transmission electron microscopy of the myocardium revealed disruption of myofibrils, chromatin condensation, and disrupted and swollen mitochondria. The cottonseed bedding contained 1,600 mg/kg of free gossypol, a concentration considered toxic for monogastric animals. The stomach content revealed the presence of gossypol, thus confirming ingestion of cottonseed. Gossypol poisoning in dogs is extremely rare and has not yet been associated with cottonseed bedding. This first documented case of gossypol poisoning in a dog, caused by the ingestion of cottonseed bedding, demonstrates how specific toxicological analysis is crucial in reaching an accurate diagnosis.