From Dog

Coccidiosis is a general term used to define infection in dogs by protozoan parasites, which are microscopic, spore-forming, single-celled parasites which possess a unique organelle (apicoplast) and thus belong to the apicomplexan class.

In this class are included;

This genus excludes Giardia spp, Tritrichomonas spp and Pentatrichomonas hominis which are anaerobic flagellated protozoan parasites.