MYOCARDIAL INFARCTION: A RESPONSE TO SOCIAL INTERACTION AMONG CHICKENS.

A study of male and female chickens caged alone, in male-female pairs, in groups of four males and in heterosexual groups of 6, 12, and 24, with a proportion of two males to one female, suggests that coronary arterial disease with myocardial infarction may be a response to social interaction, especially interaction that relates to sexual behavior. Myocardial infarcts were limited to males of heterosexual pairs and groups and to females of groups that contained 24 chickens. The lesion was found in males that died at 16 to 44 weeks of age, and in females at 32 to 43 weeks.