Oropharyngeal Necrobacillosis with Septic Thrombophlebitis and Pulmonary Embolic Abscesses: Lemierre's Syndrome in a New Zealand White Rabbit.

Lemierre's syndrome, oropharyngeal infections induced by anaerobic bacteria, leading to fatal septic thrombophlebitis of the internal jugular vein and pulmonary embolic abscesses in humans, was diagnosed in a 6-month-old, male, New Zealand White rabbit. After acute onset of anorexia, lethargy, and depression, the rabbit died suddenly despite emergency clinical care. Necropsy revealed swelling, necrosis, and abscess in the soft tissues around the left caudal mandibular ramus, oral mucosa, and molar teeth, with systemic embolic abscesses and necrosis, especially in the jugular vein, lungs, and brain. Histologic examination revealed necrosis and embolic abscesses with filamentous bacteria in the mandibular soft tissues, salivary gland, jugular veins, alveolar bone and marrow, periodontal tissues and dental pulp, oral and pharyngeal mucosa, lungs, brain, liver, myocardium, meninges, and small intestine. Bacterial culture of the mandibular abscess and heart blood yielded Fusobacterium necrophorum.