Coccidioidomycosis in a bottlenose dolphin

Area of Science:

• Veterinary Mycology
• Marine Mammal Pathology
• Infectious Diseases

Background:

• Coccidioides immitis is a fungus endemic to arid regions of the Southwestern United States.
• While infections are documented in terrestrial wildlife, cetacean susceptibility remains largely uncharacterized.
• Marine mammals can be exposed to environmental fungal spores through various routes.

Observation:

• A stranded bottlenose dolphin (Tursiops truncatus gilli) exhibited progressive respiratory distress and buoyancy issues.
• Necropsy revealed pulmonary caseous nodules and lymphadenopathy.
• Histopathology confirmed Coccidioides immitis in lung, lymph nodes, and brain tissues.

Findings:

• Diagnostic tests confirmed Coccidioides immitis infection, with positive serum antibodies and negative morbillivirus serology.
• The fungal infection, coccidioidomycosis, was identified as the cause of death.
• This case represents the first documented instance of coccidioidomycosis in a cetacean.

Implications:

• This finding expands the known host range for Coccidioides immitis.
• It highlights the potential risk of fungal infections in marine mammals, particularly those in coastal or estuarine environments.
• Further research is needed to understand transmission dynamics and clinical presentations in cetaceans.