Evaluation of the effectiveness of some drugs for the treatment of canine hepatozoonosis

Abstract

Canine hepatozoonosis is a parasitic disease, acquired by ingestion of ticks infected with protozoa of the genus Hepatozoon (H). Hepatozoon canis and Hepatozoon americanum are the two species that can infect dogs. The clinical presentation of Hepatozoon canis infection is highly variable and may be asymptomatic or show signs of mild to severe disease. In clinical hepatozoonosis, haematological tests reveal slight non regenerative anemia, marked neutrophilic leukocytosis with left shift and monocytosis. Diagnosis is made by the visualization of gamonts in neutrophils and monocytes in stained blood smears using an optical microscope. To date, there is no effective treatment for hepatozoonsis; imidocarb propionate is the most commonly used drug, although results are variable. The aim of this study was to evaluate three therapeutic options for the eradication of Hepatozoon spp. from blood of infected dogs. Three drugs (imidocarb dipropionate, toltrazuril and spiramycin) were evaluated in 18 naturally infected dogs. In all treated dogs the infection averages decreased, showing similar mean values of infected leukocytes. The statistical analysis showed a significant difference only in the treatment of this parasitosis with imidocarb dipropionate. It is concluded that none of the drugs are fully effective in removing the parasite from the blood, but imidocarb dipropionate
showed the best results.