Immunobiology of Domestic Animals as Affected by Hot and Cold Weather

ADVERSE weather conditions, such as rapid changes or fluctuations in ambient temperature, cold, rainy, windy conditions or constant hot or cold temperatures, increase the susceptibility of domestic animals to some economically-important livestock diseases. Scientific research has demonstrated that hot and cold weather affect both passive- and active-antibody-mediated immune events. A complex array of variables and interactions determine whether the stressor will cause immunoenhancement or immunodepression. However, the ultimate outcome of these stress-induced changes has been shown to depend on the type of immunizing agent, timing of the stressor relative to induction or expression of the immune response and length of time that animals are exposed to hot or cold ambient conditions. These results suggest that environmental stressors trigger non-specific physiologic changes which affect the immune system. These changes in immune function may then alter resistance of animals to infectious and neoplastic diseases.