Alteration in Cellular Immune Function Associated with the Simulated Transportation of Dolphins
Brad Fenwick, DVM, MS, PhD; J.P. Schroeder, DVM
Transportation of captive dolphins is a necessary part of their routine
management and care. While opinions may differ as to its effect on homeostasis, many current
beliefs are based on subjective observations. To date, no techniques are available for
objective evaluation of the influence of transportation on dolphin immune function.
This study was designed to determine: (1) if the lymphocyte
transformation assay (LTA) could detect changes in dolphins' immune function and (2) to
evaluate the degree and duration of immunosuppression associated with a simulated
transport.
The subjects were two adult, healthy captive dolphins. Prior to, during
and for three weeks following a 12 hour simulated transport period (out of water), peripheral
blood lymphocytes were periodically isolated, cryopreserved, and LTA performed using
techniques previously developed for this purpose. Blood and serum samples were also collected
and evaluated for hematologic and biochemical changes.
No behavioral, hematologic or biochemical abnormalities were noted
following the simulated transportation period. However, a decrease in lymphocyte
transformation response was detected. The most severe depression of lymphocyte activity
occurred approximately 5 days post transport and returned to normal levels by day 11.
While additional studies are needed to fully characterize the effects of
stress on the dolphin immune system, our results provide, for the first time, a method of
determining the changes in immune function in individual dolphins. Our findings do not
correlate the depression of lymphocyte activity that was observed with the degree of
decreased resistance to disease. Future studies will be necessary to relate the degree of
lymphocyte transformation measured to immunosuppression and decreases in disease resistance.
Such techniques and determinations should play a central role in the development of improved
dolphin management systems that optimize disease resistance.