Infection of Dogs with Hepatozoon canis and Other Haemoprotozoan Parasites in Ibadan, Nigeria

Abstract

Hepatozoon canis gametocytes were identified in the circulating neutrophils of eight naturally infected dogs presented at the Veterinary Teaching Hospital, University of Ibadan, Ibadan, Nigeria. The dogs were aged between four months and three years and showed varied clinical signs and haematological findings. Clinical findings were mainly: weakness, recumbency, anorexia, dehydration, fever, pale mucous membranes, jaundice, and congested ocular membrane. Varying numbers of the brown dog tick (Rhipicephalus sanguineus) were found on the dogs. Hepatozoon canis parasitaemic level was determined by counting 200 neutrophils in Giemsa stained blood smears using the light microscope. Parasitaemia varied from 0.2-15%. The haematological findings in the dogs were mainly non-regenerative to regenerative anaemia (3/8), thrombocytopaenia (6/8), leucoytosis (3/8), neutrophilia with left shift (2/8), lymphocytosis (2/8), and monocytosis (1/8). In addition, five (5/8) of the dogs were co-infected with Babesia canis (1/8), Ehrlichia ewingii (3/8) and E. platys (1/8). Since light microscopy is not a very sensitive method for the detection of these parasites, these findings suggest that tickborne co-infection with more than one haemoparasite is a common phenomenon in this endemic environment.

Keywords: Hepatozoon canis, haemoparasites, tickborne co-infection, dog