Computerized Tomography of a Sinus Abscess in a Pygmy Sperm Whale (Kogia breviceps)
IAAAM Archive
Timothy Tristan1; Craig Pelton2; Ruth Ewing3
1Marathon Veterinary Hospital, Marathon, FL; 2Marine Animal Rescue Society, Florida International University Marine Lab, North Miami, FL; 3National Marine Fisheries Service, SEFSC, Miami, FL


On June 21, 2000 a female pygmy sperm whale calf (Kogia breviceps) stranded in Key West, Florida. Initial assessment revealed that she was dehydrated and emaciated with numerous lacerations from beaching. Additionally, there was a raised area on her melon, craniolateral to the blowhole. This area was firm, oval, and measured 7cm x 10cm x 1 cm. In July 2000, a full body ultrasound was performed; however, the mass was not visible due to the air interface on the medial surface, deep to the blubber layer over the area of the sinus.

Over the next four months she was rehabilitated to an acceptable level, allowing more invasive diagnostics. A CT scan was scheduled for October 15, 2000. She was sedated using Versedã 0.025mg/kg IM (Roche Laboratories, Nutley, New Jersey, USA) and transported to Lower Keys Medical Center in Key West, Florida for scanning. During the scanning procedure a second dose of Versedã was administered at 0.025mg/kg IM to maintain a moderate level of sedation. A moderate level of immobilization was reached and maintained for approximately 45 minutes at the combined dose.

The in vivo CT scans were conducted for approximately 30 minutes using a spiral protocol at 120 kV, 250 mA, 1.0 s, in 3.0 mm sections for nasal sacs; at 120 kV, 250 mA, 1.0 s, in 3.0 mm sections for the trachea; and at 120kV, 250mA, 1.5 s, 10.0 mm for the thoracic cavity. The reversal agent, Romazicon© 0.001mg/kg IM (Roche Laboratories, Nutley, NJ, USA), was administered following the CT scan. Her recovery was uneventful and complete within 5-10 minutes of reversal administration.

The CT scan revealed a focal mass within the right sinus with associated fluid accumulations in the right and left sinuses. These changes were consistent with an exudative sinusitis with abscessation. The mass was aspirated and a bloody purulent exudate was obtained for analysis. Cytologic examination of the needle aspirate revealed budding yeast admixed with bacteria. Routine aerobic and fungal cultures were also conducted. Culture results included a significant growth of Candida albicans, Pseudomonas aeruginosa, Klebsiella sp., and Proteus mirabilis. The CT examination revealed no other significant findings in the larynx, trachea, bronchi, or lungs. On October 31, 2000, she died suddenly in an unrelated accident.

On microscopic examination of necropsy samples, there were changes suggestive of regional and systemic dissemination with mild to moderate multi-organ lympho-plasmacytic and lympho-histiocytic inflammatory changes in the trachea, lung, and heart. Necropsy routine aerobic and fungal cultures of the lung had heavy growth of Escherichia coli, Proteus mirablis and Candida albicans. Necropsy routine aerobic and fungal cultures of the nasal sac and abscess had heavy growth of Proteus mirablis, Enterobacter agglomerans, and Candida albicans. Further macroscopic examination and characterization of the nasal sac changes are pending future gross dissection.


We would like to thank the volunteer members of the Southeastern United States Marine Mammal Stranding Network especial those representing Marine Animal Rescue Society and Wildlife Rescue of the Florida Keys whose dedicated efforts during Summer's rehabilitation were greatly appreciated. We appreciate the generous contribution of the radiology department at the Lower Keys Medical Center in Key West, Florida for the use of their computerized tomography scanner and other technical assistance, especially the efforts and participation of radiologist Drs. Hernandez and Falciano and radiology technician Suzie Panrock. We are especially grateful to Dr. Darlene Ketten for her contributions and expert technical advice regarding marine mammal computerized tomography. Additionally, we want to thank the many veterinarians whose advice and support enhanced our rehabilitative efforts for Summer including Drs. Greg Bossart, Forrest Hayes, Mike Walsh, Forrest Townsend, and Douglas Mader.

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Timothy Tristan

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