Streptococcus phocae–Associated Pyothorax Secondary to Verminous Perforative Esophagitis in a Juvenile Harbor Seal (Phoca vitulina) in the UK

A stranded juvenile harbor seal (Phoca vitulina) was necropsied following acute dyspnea and death. Necropsy revealed an esophageal perforation caused by fourth-stage Contracaecum osculatum larvae with Streptococcus phocae-associated pyothorax and aspiration pneumonia. Pyothorax is uncommon in seals, and S. phocae is considered a novel etiology, secondary to verminous esophageal perforation.