Cestodes of dogs and cats in North America.

Cestodes are hermaphroditic flatworms (tapeworms) consisting of a scolex, neck region, and repeating segments. Cestodes lack a mouth, intestine, and body cavity. Life cycles are indirect, with the definitive host acquiring the adult form of the tapeworm by the ingestion of the larval metacestode stage contained in an intermediate host. This article describes the cyclophyllidean and pseudophyllidean groups of infective cestodes. Tapeworm infection is common in dogs and cats in North America. Infection rarely results in clinical disease, but animals infected with tapeworms should be treated. Echinococcosis, though infrequently diagnosed, remains a serious human health threat in North America.