How do dogs typically acquire infection with Sarcocystis spp.?

Dogs typically acquire infections with Sarcocystis spp. by ingesting an intermediate host that contains sarcocysts in its muscle tissue. Sarcocystis is a genus of protozoan parasites that require a definitive host (in this case, dogs) and an intermediate host (often herbivores like cattle or pigs) to complete their life cycle. When dogs consume the muscles of these infected intermediate hosts, they take in the cysts, leading to the infection.

This transmission method is crucial for understanding the life cycle of Sarcocystis as it emphasizes the role of intermediate hosts in the parasite's propagation. The ingestion of contaminated food or direct contact with infected animals does not serve as the primary means of transmission for Sarcocystis spp., nor does inhalation of spores, which is not a typical route of infection for this protozoan.