Observations on Hepatozoon canis in Rhipicephalus sanguineus

Rhipicephalus sanguineus ticks that fed on dogs infected with Hepatozoon canis either naturally or experimentally, revealed the presence of oocysts of the parasite in the haemocoele. Oocysts were multisporocystic (132–148) with spherical to oval sporocysts that contained 8–16 sporozoites. H. canis was experimentally transmitted to a dog through oral feeding of infected adult R. sanguineus ticks and transtadially from nymphs to adult R. sanguineus ticks. Transtadial transmission from larvae to nymphs could not be effected. Sporocysts in various stages of development were observed as early as 8 days post-infection in ticks.