Abstract

On June 21, 2000, an orphaned, female pygmy sperm whale (Kogia breviceps) calf stranded in Key West, Florida. On presentation the calf was dehydrated, malnourished, weak, and had a small abscess on her head. Based on her total length, 162cm, her age was estimated between 3 and 6 months.

Upon presentation the immediate concern was rehydrating her with the administration of 500 to 700 mls of water, piedialyte, and diluted squid gruel (<0.1kg squid/1 water) by gastric tube 8 to 12 times a day. Based on past traumatic consequences ~ induced by repeated tubings, attempts to wean her onto a bottle were made. After development of a nipple apparatus she began taking her feedings from the bottle and was eventually conditioned to position herself at a feeding station.

The initial nutritional plan was based on three concepts; past experience with Kogia calves, past experience with Tursiops calves, and literature. A quick literature review suggested the daily caloric needs of Kogia calves are 60 to 80 kcal/kg of body weight² and 80 to 100 kcal/kg of body weight 6. The target weight gain was set at 0.5 kg/day to avoid obesity related diseases.⁶ Unfortunately, without logistical access to a scale, length and girth measurements were used to estimate weight and assess weight gain.

Past experiences using a Kogia formula 2 and recent experience with a Tursiops calf 3 led to the decision to offer her a modified Nina formula 5. In this case, the Nina formula was modified by replacing the herring and salmon oil with squid and cod liver oil, respectfully. Analysis of this formula showed its caloric content to be 1.5 kcals/ml. In addition to the formula, the calf was offered squid gruel (0.42 kcal/ml) and whole squid (beak and pen removed; 0.80 kcal/g).

On August 1st a hanging scale was obtained and equipped to begin monitoring her weight by having her voluntarily swim into an associated stretcher. Based on her initial weight of 73.2 kg (Figure 1) she was receiving 93.2 kcal/kg body weight. During August she had an average weight gain of 0.78 kg/day, weighing 97.3 kg on August 31st, while ingesting between 6000 and 8000 kcals/day (Figure 1). Over this month she received between 67.5 and 89.2 kcal/kg/day (Figure 2). Throughout this period her appetite was consistent but her weight gain, feeding behavior, and observed activity level were abnormal for healthy cetaceans being maintained at captive facilities. She seldom ate all the food offered to her over an entire day, breaking station or playing with her food towards the end of feeding sessions. She also spent increasing amounts of time in a resting state. On September 4 th she refused feedings and reduced her caloric intake for the day to 2310 kcals (Figure 1). Her feed refusal continued over the next week. Based on past experience 4 with the above stated behavior and multiple physical exams and blood results over that week that were all within normal limits it was believed that her feeding refusals were due to food satiation. On September 8th she weighed 93.4 kg (Figure 1), a loss of 3.9 kg in 8 days but her appetite was improving.

Figure 1

The decision was made to reduce the calories offered to between 50 kcals/kg body weight a day. Over the next two months her intake level was adjusted accordingly based on average daily kcal/kcal/day received, average kg/day of weight she gained, her feeding behavior, and her activity level. During this time she consistently ingesting between 46 and 48 kcal/kg/day (Figure 2). This intake level allowed her to gain approximately 0.5 kg/day over the 7 weeks (Figure 2) leading to an October 25 th weight of 116.4 kg (Figure 1). Behaviorally, she had a more consistent appetite, an increased activity level, and an increased degree of alertness then when she was ingesting a higher amount of kcals/kg/day. Exams in preparation for a CT scan and a facility transfer during the last 2 weeks of October both showed her to be in good physical condition except for the original cranial abscess that had grown throughout the rehabilitation process 7. During her 4 months in rehabilitation she grew 31 cm's in length and from August 1st to October 25th, gained 43.2 kg.

figure 2

Although the literature provides good baselines on which to initiate a nutritional plan, care should be taken in closely monitoring an individual's feeding behavior, activity level, and weight gain to determine the individual's specific caloric needs. In this case the calf's behavior and physical condition after 4 months in rehabilitation support a weight gain of 0.5 kg/day weight for Kogia calves but her daily caloric needs of 46 to 48 kcals/kg of body weight to maintain this weight gain were well under those published.

Acknowledgements

The authors wish to thank the dedicated volunteers of the Southeast United States Marine Mammal Stranding Network, the Marine Animal Rescue Society, and Wildlife Rescue of the Florida Keys who assisted Summer's care. Elaine Allen, Melissa Towle, Renee Roberts, and Myrto Argyropoulou receive special thanks for helping train and maintain Summer's husbandry behaviors. In addition we would like to thank Howard Rhinehart (Mote Marine Laboratory), Gregory Bossart, VMD, Ph.D. (Harbour Branch Oceanographic Institute) and Forest Townsend (Bayside Animal Hospital) for past and present consultations on calf rearing.

References

1.  Ewing, R. Unpublished data on linear esophageal ulcers.

2.  Gorzelany, J.F., H. Rhinehart, F. Townsend, and M. Wells. 1995. Development and administration of a nutritional formula for a stranded pygmy sperm whale (Kogia breviceps) calf. IAAAM Proceedings. 26:31-32.

3.  Pelton, C. Unpublished data on successful Tursiops calf rehabilitation.

4.  Pelton, C. Unpublished data working with Orcinus orca and T. truncatus.

5.  SeaWorld. Personal communication.

6.  Townsend, F.I. 1999. Hand-rearing techniques for neonate Cetaceans. In: Zoo and Wild Animal Medicine: Current Therapy 4, Fowler, M.E. and R.E. Miller (eds.). W.B. Saunders Company., Philadelphia, 493-497.

7.  Tristan, T. 2001. CT scan of a Pygmy Sperm Whale (Kogia breviceps). IAAAM Proceedings. (in publication).