An 8-year-old male bottlenose dolphin presented with mild behavioral changes. Initial bloodwork revealed mild leukocytosis resulting in administration of oral antibiotics. Consecutive blowhole cultures were positive for Cunninghamella bertholletiae, with abundant nonseptate, hyphal structures noted on cytology prompting oral antifungal therapy. Rhinoscopy revealed mucous in the sinuses and twice daily nasal flushes with dilute betadine began. Initial melon and thoracic ultrasound and radiographs revealed no abnormalities; however, follow-up radiographs revealed an increased bronchial pattern and 2 nodules in the left cranial lung field leading to antifungal nebulization therapy. Follow-up radiographs were unremarkable, but oral and inhaled antifungal therapy continued as cytology and cultures remained positive for Cunninghamella. Bronchoscopy was performed; moderate exudate extended into the left mainstem bronchus to at least the 3rd generation airways. Subsequently, a computed tomography scan of the head and thorax revealed left-sided peribullous sinusitis and a multifocal interstitial pattern with occasional nodules consistent with fungal pneumonia and early bronchiectasis. Cunninghamella bertholletiae is an opportunistic Mucorales fungus often causing significant, persistent pulmonary disease in immunocompromised humans. While not a common cause of illness in cetaceans, Cunninghamella bertholletiae has been detected in subclinical animals with one confirmed pulmonary infection in a killer whale. Evaluation of this dolphin's immune function in 2010 and 2011 suggested that he was immunocompromised, which may have contributed to the establishment of this opportunistic infection. To date, inhaled and oral antifungal therapy continues and periodic diagnostics are performed to track the infection and direct therapy. The dolphin is currently asymptomatic.
We would like to thank Drs. Bill Van Bonn, Chris Dold, Tim Tristan, Forrest Townsend, Lydia Staggs, Mike Walsh, Jay Sweeney and Sophie Dennison for their assistance with this case as well as the Animal Training and Animal Health staff at Georgia Aquarium.
* Presenting author