Fatal gangrenous oesophageal necrosis and aspiration pneumonia diagnosed at postmortem in a captive African lion (Panthera Leo): A case report

Gangrenous oesophageal necrosis (black oesophagus) is a rare condition in domestic and wild animals, but has been widely investigated and documented in humans. There are no reports of this condition in the African lion (Panthera leo). This case report describes a fatal occurrence of the condition in a 9-year-old male captive African lion with a history of severe dental caries that caused recurrent sepsis and post-prandial emesis. At first presentation, the haematology showed marked thrombocytopaenia and moderate neutropaenia and lymphopaenia suggestive of waning immunity associated with a systemic viral disease most likely Feline Immunodeficiency Virus (FIV). The condition persisted for about three years during which there were clinical interventions which included dental debridement and flushing, antibiotics, and analgesics. In spite of these interventions, the animal eventually presented with persistent vomiting and inappetence. Further therapeutic intervention, including antimicrobial therapy based on microbial culture and sensitivity did not offer any relief. The lion died 35 days after it was presented with postprandial emesis and inappetence. Postmortem examination revealed cachexia, severe dental wear, and diffuse greenish-black gangrenous necrosis of the entire oesophageal mucosa, with impaction of the distal oesophagus by approximately half a kilogram of rotting meat and 450ml of brownish fluid. Histopathology showed necrosis and inflammation of the oesophageal mucosa and submucosa as well as aspiration pneumonia. This case highlights that severe dental disease and immunosuppression can be associated with oesophageal impaction, ischaemia, and gangrenous oesophageal necrosis in the African lion. It also underscores the critical importance of proactive dental care and dietary management of captive lions to prevent this fatal condition.