Introduction to Parasitology

Summary of important information about specific life cycles

Table 2 Dipylidium caninum
- dog & cat tapeworm
Eimeria bovis
- coccidian of cattle
Hematopinus suis
- pig louse
Babesis canis
 - dogs
Route(s) of entry to the host 1. Ingestion of intermediate hosts (fleas and lice) containing cysticercoids. 1. Ingestion of sporulated oocysts Direct contact with an infested host 1. Injection of sporozoites by feeding female ticks (Rhipicephalus)
Predilection site in the definitive host Small intestine Small intestine (Asexual reproduction)
Large intestine (sexual reproduction)
Skin and hair coat Red cells (asexual reproduction)
Route to the predilection site Direct development in the small intestine after  ingestion of intermediate hosts.  Direct development in the intestine None -all life cycle stages occur on the host Invasion of red cells by sporozoites
Route of exit from the host In the feces of the host In the feces of the host None - all life cycle stages occur on the host. Adults and nymphs move to another host via direct contact Infected red cells are ingested by feeding ticks
Stage entering the host (infective stage) Cysticercoid Sporulated oocyst All stages except eggs Sporozoites
Stage leaving the host (diagnostic stage) Egg oocyst All stages except eggs Trophozoite in host red blood cells



Parasites and Parasitic Diseases of Domestic Animals
Dr. Colin Johnstone (principal author)
Copyright 1998 University of Pennsylvania
This page was last modified on January 24, 2000