Shortly after ingestion of sporulated oocysts, invading sporozoites penetrate epithelial intestinal cells and endogenous development proceeds with 2-4 merogonies and gamogony
. Observations of the animals as well as necropsies to determine the location and type of the lesions (lesion scores) in each flock are important to confirm diagnosis and identify the species virulence upon outbreak.
(19) Developmental stages in the definitive host consist of merogony, gamogony
, fertilization, and formation of new oocysts in the intestinal epithelium, (1,14) and it takes 7 to 13 days to complete.
The intestinal phase of the infection occurs only in felines and exhibits a typical intestinal coccidian life cycle consisting of merogony and gamogony
. The tissue phase of the infection can be transmitted congenitally to offspring and to other intermediate hosts through carnivores (Al-Daoody 2012).