On 7 August 1991 an 11 year old female beluga. whale (Delphinapterus leucas) delivered a male calf in the company of a second, more experienced, 21 year old, pregnant, beluga whale. During the ensuing 8 hours the second whale directed progressively more aggressive behaviors towards the calf. She was separated leaving the mother and baby as sole occupants of the pool. Rake marks, inflicted by the second adult, were noted on the right side of the calf's peduncle.

The calf did not nurse until 33 hours post-partum. Prior to that event, weight loss became increasingly obvious with a decrease of body mass in the neck, dorsal lumbar area, the abdomen, and the area of the fetal folds. The loss of body mass progressed to a stage which permitted visualization of the pectoral bones and increased prominence of the skull between the blowhole, and the nuchal crest. However, with the onset of regular nursing the weight loss began to reverse over the ensuing days.

At 22 days post-partum the peduncle lacerations were more prominent and skin sloughing was observed on the ventrum, genital area, peduncle, and pectorals. However, this shed of skin progressed to encompass most of the body and resulted in a healthier layer of skin. On 14 August the 21 year old beluga whale gave birth to a male calf. This second calf went through a similar shed at a time which corresponded to that of the first. In general, the first calf was shorter, had a rounder midbody, and poorer skin quality than the second calf, but did seem to be steadily improving in vigor, weight gain, and skin quality.

By 23 September 1991 at 47 days of age the abdomen was noted to be enlarged, pendulous, and obviously abnormal. There was a resumption of skin shed with multiple layers of tissue exposed.

The calf spent more time at the surface and was unable to dive to the bottom of the tank with the dam. Milk was observed spraying from the dams mammary glands between and following nursing episodes. Medical intervention was elected at this point. The water was dropped to a depth of approximately 1.4m and the calf was caught by hand and restrained while the dam was free to swim. Attempts were made to keep the dam separated from the examination area with the use of restraint boards. The medical evaluation included venipuncture for complete blood count, biochemistry, erythrocyte sedimentation rate, reticulocyte count and culture. Hematology values are summarized in Table 1.

Table 1. Beluga Whale Calf Hematology

A stomach tube was passed and milk samples collected for direct microscopic exam, cytology, and culture. Swabs from the blowhole, genital slit, and rectum were also collected for culture. A fecal sample was examined microscopically and sloughed skin samples were preserved in formalin for microscopic exam. The calf's weight was 76.36 kg. Consecutive weights are listed in Table 2. Therapeutics included benzathine and procaine penicillin G, approximately 20,000 units/kg each i.m., enrofloxacin 6.3 mg/kg i.m., and levamisole 0.17 mg/kg i.m. In addition the dam was begun on 1.7g bid of enrofloxacin per os.

Table 2. Beluga Whale Calf Weights

On 25 September the calf was again examined. The abdomen was less distended. Repeat samples of blood and stomach contents were obtained. The calf received 15.7 mg/kg trimethoprim sulfadiazine, approximately 20,000 i.u./kg each of benzathine and procaine penicillin G and 0.1 mg/kg levamisole i.m. The dam's enrofloxacin dose was increased to 3.4 g bid. In addition the mother was supplemented with 20 mg of folic acid sid.

On 27 September the calf's therapeutics were repeated. Blood samples and gastric contents were again obtained. Results of aerobic cultures from 23 September grew a Vibrio sp. from the blowhole, genital slit, rectum and blood. The organisms were sensitive to enrofloxacin and trimethoprim sulfadiazine. The anaerobic blood cultures yielded a clostridial growth which would presumably be sensitive to penicillin. The calf's attitude and vigor improved daily. Trimethoprim sulfa was continued every other day until 5 October and benzathine and procaine penicillin G every other day until 7 October. The dams enrofloxacin was continued bid until 17 October 1991. The abdominal distension resolved over the ensuing 3 weeks and the skin shed decreased leaving a healthier outer layer by 24 October. Weight gain also resumed.

On 11 December the calf was judged to be playful, and visually within normal limits except for some roughened, irregular skin surrounding the blowhole. Pool water cultures grew a large number of fungal colonies which were postulated to be secondary to the long term antibiotic therapy administered to the dam. Calf regurgitation was observed. A piece of regurgitated tissue collected from the water was submitted for histopathologic exam. The tissue consisted of stratified squamous epithelium covered with a mat of fungal hyphae compatible with Candida sp. Nystatin was administered at an oral dose of approximately 29,000 units/kg five times daily.

On 7 January 1992 the animal seemed clinically within normal limits, with a body weight of 100.45 kg. However, cytology of a gastric sample taken two days previously on 5 January 1992 revealed further budding yeast. Fluconazole was administered at approximately 2.0 mg/kg via stomach tube then followed by 1.5 mg/kg sid per os for 14 days. Nystatin was continued and Acidophilus sp. was added four times daily. Fungal cultures submitted on 7 January revealed growth of Aspergillus fumigatus from both stomach and skin of the calf.

On 28 January 1992 the calf was re-evaluated. Cytology and culture of fecal and gastric content samples along with histopathologic evaluation of sheets of epithelium retrieved via stomach tube failed to demonstrate any fungal organisms.

Conclusion

To date the calf has continued to gain weight and interact normally with the dam and trainers. Preliminary evaluation of the calf's enrofloxacin antibiotic levels measured via blood and gastric contents suggest that treatment of the dam resulted in therapeutic blood levels in the calf by trans-mammary transmission. The cause for the repeated medical problems of this calf can be speculated. The 33 hour delay in the onset of nursing may have decreased or totally inhibited the post-partum absorption of colostral antibodies. In addition, the trauma suffered in the first few hours following birth, though visibly minor, may have served as a nidus for sepsis. The fungal infection may well have been due to the long-term, multiple antibiotic regimen necessary to combat the generalized infection.

Acknowledgements

Special thanks to Dr. Bonnie Raphael, Animal Health Center, New York Zoological Society, New York, U.S.A., Dr. Jim McBain, Sea World, San Diego, California, U.S.A. and Dr. Michael Walsh, Sea World, Orlando, Florida, U.S.A. for their timely advice and assistance. Thank you also to Dr. Tracey McNama.ra, Pathology Section Head, Animal Health Center, New York Zoological Society, New York, U.S.A. for her rapid and accurate evaluation of biopsy materials. Most important to this success were tremendous efforts and dedication of Kevin Walsh, Martha Hiatt-Saif, Guenter Skammel, JoAnne Basinger, Dennis Maroulas, and the entire staff of the New York Aquarium.