The failure of the coccidial sexual stages to develop in Nubian goat kids experimentally
infected with mixed Eimeria spp. is known as crowding phenomenon. In such cases the
asexual coccidian stages will continue to develop and form new merizoites to invade new
epithelial cells forming meronts. This process continues repeatedly, destroys all epithelial
cells causing the clinical disease without formation of sexual stages. In histological sections,
meronts are found filling all epithelial cells and no other sexual stages are seen. So, no
oocysts are discharged in faecal samples.