ABSTRACT
There are many host hormones and effecter molecules other whose altered productions are likely important in the pathophysiology of coccidia infections. A large number of investigations have reported descriptive pathology of enteric coccidia infections in birds and mammals. The pathogenic effects of coccidia that primarily inhabit the villus epithelium are more variable. Increased mitotic activity leading to increased cell turnover is the most common change reported in coccidia infections. There is also an increased rate of stem cell differentiation so that goblet cell hyperplasia and increased numbers of enteroendocrine cells are detected. Metabolic changes accompany the structural changes in the intestinal mucosa that arise during infection by intestinal coccidia such as E. acervulina in chickens. The pathological effects of enteric coccidial infections in chickens are not restricted to effects on the gut nor do they simply cause reduced weight gain because of anorexia or malabsorption.
