Tick injects trophozoites into bloodstream while feeding. This cycle continues indefinitely Tick ingests zoites while feeding, the zoites penetrate the gut wall and undergo schizogony.
All instars can transmit zoites.
Recovered individuals can remain mildly infected for a long time, thus maintaining a premune status. Copyright 1997 all rights reserved. Published by RM Corwin and Julie Nahm, University of Missouri College of Veterinary Medicine.