**4. Summary**

The present study on ticks collected from 35 dogs affected with *Ehrlichia canis* were identified as *R. sanguineus* based on the typical morphological features which included hexagonal basis capitulum, bifid first coxae, presence of adanal shields, posterior "U" shaped genital aperture and the presence of adanal glands. Hence, it is concluded that *R. sanguineus* ticks were responsible for transmitting *E. canis* infection in dogs of Puducherry.
