Leslie M. Dalton, DVM; Todd R. Robeck, DVM
A 35 day old, 234 kg, female killer whale calf was presented with signs of lethargy, inappetence and an elevated respiratory rate on December 25, 1994. The birth and rearing was uneventful until December 14, when nursing times decreased below normal levels. By December 15th, nursing had returned to near normal. On December 25, nursing ceased and the calf's respiratory rate began to climb well above normal. On December 26th, a physical examination was performed which included a blood sample for hematology and chemistries, a fecal for cytology and culture, and cultures of exhaled air (blow plate) for identification and sensitivity of organisms in the respiratory tract. Antimicrobial therapy was initiated based on a tentative diagnosis of pneumonia of unknown etiology.
The calf's breath was foul smelling during the physical examination on the afternoon of the 26th. Small pieces of white mucous were expelled during exhalations. Treatment at that time consisted of 100 mg of purified killer whale IgG intravenously, amikacin, 7.7 mg/kg intramuscular bid/ and itraconazole, 5 mg~kg per os sid via stomach tube. Two liters of 0.9% saline were also given due to an elevated BUN and low sodium and chloride. Some of the notable hematology and chemistry values are presented in Table 1. A large volume of gas was released from the stomach of the calf through the stomach tube during treatment. Formula was given to the calf using a stomach tube again during the evening. Treatment during the morning of the 27th consisted of amikacin, itraconazole, and formula. No nursing was observed throughout the 27th or the morning of the 28th. The calf was separated from the mother to facilitate treatment and Ultrasonography at approximately 1400 hours on the 28th. It died on the afternoon of the 28th.
Granulomatous lesions were observed throughout the lungs on gross necropsy as well as a thickened pulmonary pleura, pleural effusion, and generalized lymph node enlargement.
Clostridium perfringes was isolated from the thoracic fluid, abdominal fluid, and the thoracic lymph nodes. Aeromonas sobria was isolated from the spleen, abdominal fluid, liver, kidney, lung, and mediastinal lymph nodes. Escherichia cold was isolated from the thoracic fluid, urine, spleen, liver, kidney, lung, and the mediastinal lymph nodes. Enterococcus faecium was isolated from the urine, kidney, and mediastinal lymph nodes. Enterococcus durans was isolated from the kidney and mediastinal lymph nodes.
Morganella morganii was isolated from the urine, abdominal fluid, and mediastinal lymph nodes. Nocardia asteroides was isolated from the lungs and mediastinal lymph nodes.
Histologically, there were pyogranulomatous lesions in the lungs, pulmonary pleura, thyroids, spleen, adrenals, heart, and lymph nodes.
Clinically, it's difficult to determine which came first, the nocardia or the other bacteria. Histologically, it is evident that nocardia was well established and chronic in duration.