Background and objectives: Hepatozoonosis caused by Hepatozoon canis and Hepatozoon americanumis a protozoan parasite infecting carnivores worldwide. Hepatozoon canis is endemic in the Middle-East. Dogs usually get infected by ingestion of Rhipicephalus sanguineus sensu lato ticks which contain oocysts of the parasite. Although H. canis infection is usually subclinical in young animals and in the case of high parasitemia,the signs may include anaemia, fever, poor appetite, weight lossand enlarged lymph nodes. The diagnosis is often based on the microscopical findings of a stained blood smear.Aim of this study was to examine blood of rescued dogs in shelters in Hamedan, Kermanshah and Khuzestan provinces for the presence of this parasite. Methodology: From October 2018 toJune 2019, a total of235 EDAT blood sample (100 from Hamedan, 55 from Kermanshah and 80 from Ahvaz)were taken from dogs kept in shelters and breeding centers.Giemsa stained blood smears were examined microscopically. Results: Gamonts of Hepatozoon spp. were observed in 12.34% (29/235) of the neutrophils in blood smears.Infection of dogs was 45.45% (25/55) in Kermanshah and 4% (4/100) in Hamedan. No infected dog was detected in Ahvaz. Co-infection with Hepatozoon and Cercopithifilaria bainae, a dermal filaroid of dogs, was detected in 6 dogs (20.69%). Discussion and Conclusion: Canine hepatozoonosis was previously reported from Khorasan (infection rate=1.57% and 8% in two studies), Ardabil (infection rate= 23.07%) and Tehran (infection rate= 22.06%).Our study provides information about H. canis infection in dogs in west and south-west of Iran. This parasite has been also detected in a Persian leopard (Pantherapardusciscaucasica) suggesting that wild carnivores have role in the epidemiology of disease in the country.
