U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific, San Diego, CA, USA
To present a case report on the clinical presentation, diagnosis and treatment of Brucella sp. identified from a pulmonary abscess in a bottlenose dolphin (Tursiops truncatus).
A 27 year-old female bottlenose dolphin presented with an acute history of partial anorexia and abnormal respiratory rate and character. Physical and ultrasonographic examinations revealed a 3 x 3 x 4 cm hypoechoic mass deep to the pleural lining in the left lung field approximately 20 cm cranial to the dorsal fin. Routine CBC and blood chemistries were consistent with mild inflammation.
Using ultrasound guidance, multiple fine needle aspirates (FNA) of the mass were performed and samples sent for bacterial and fungal culture, Microseq for bacteria, and ultimately Real Time PCR for Brucella sp. In-house cytology revealed a moderate amount of neutrophils and lymphocytes with no causative agent. All cultures returned negative results; however, two separate PCR amplifications identified Brucella sp. Brucella titers were also performed on banked serum, acute, and post treatment blood samples. The titers revealed the animal was exposed prior to joining the Navy Marine Mammal Program and did not increase during the recent illness.
During the FNA procedures, diluted amikacin (250 mg in 10 ml of 0.9% sodium chloride) was infused into the abscess. The animal received a third generation cephalosporin (Cefpodoxime 7.5 mg/kg PO q 24 hr) and anti-fungal (fluconazole 4 mg/kg PO q 24 hr) oral medications until the Brucella sp. was identified. While the size of abscess appeared smaller, the drug protocol was switched to a more traditional anti-Brucella protocol of doxycycline (2.5 mg/kg PO q 12 hr) and rifampin (4 mg/kg PO q 24 hr). Follow-up with ultrasound continues to show decrease in the size of the abscess.
We thank our colleagues at the Navy Marine Mammal Program: Sam Ridgway, Stephanie Venn-Watson and Katie Frank for their assistance and guidance with treatments and care of this animal. Special thanks go to the Records Department, Risa Daniels, Kevin Carlin, and Chris Hammell, for their tireless work in sample submission and data collection for this case.