Haematological alterations in dogs infected with Hepatozoon canis

Abstract

The hepatozoonosis is a disease that mostly affects domestic carnivores, caused by the protozoan Hepatozoon spp that has ticks of the species Riphicephalus sanguineus as the main vector. In Brazil, the Hepatozoon canis has already been diagnosed in several states and the confirmation of hepatozoonosis is made through the parasite visualization on blood smears. The hematologic changes described in infected dogs are anemia, leukocytosis and thrombocytopenia. For being little investigated, the disease is often discarded as clinical suspicion, compromising the clinical diagnosis. This study aimed to analyze blood counts perfomed from March to August 2014, in Clinical Pathology Laboratory of the Federal University of Lavras searching for the presence of H. canis gamontes and crossing these results with the haematologicals alterations presents in the positive animals. Of 399 samples examined, in six were found Hepatozoon canis in the blood smear, hematological changes observed in these six animals were: normochromic normocytic anemia (n=3); red blood cells nucleated, anisocytosis and polychromasia of red blood cells (n=3); leukocytosis (n=5 and this neutrophil leukocytosis in 4 of samples, where n=4 of those occurred regenerative left shift by neutrophilia in n=4 of samples with a left shift regenerative in n=1; lymphocytosis (n=3); lymphopenia (n=1); monocytosis (n=3); monocytopenia (n=1); eosinopenia (n=2); eosinophilia (n=2 thrombocytosis (and thrombocytopenia (n=2). As a control group it was analyzed the haematological results of 20 animals not infected with Hepatozoon canis, received in the same period, and the average of haematological parameters found in them were: 7.17x106/mm³ (RBCs); 47.63% (packed cell volume); 15.86g% (hemoglobin); 11,007/mm³ (total leukocytes); 7668/ mm³ (segmented neutrophils); 215.5/mm³ (band neutrophils); 532/mm³ (eosinophils); 2107/mm³ (lymphocytes); 384/mm³ (monocytes) and 354000 (platelets). The averages for sample group of infected animals were: 5.38x106/mm³ (RBCs); 37.3% (packed cell volume); 12.38g % (hemoglobin); 28,200/mm³ (Total leukocytes); 118,983.5/mm³ (segmented neutrophils); 938.25/mm³ (band neutrophils); 1352.5/mm³ (eosinophils); 5000/mm³ (lymphocytes); 1137.16/mm³ (monocytes) and 404333 (platelets). The values observed in the control group were different from the ones observed in the infected animals, demonstrating a lower average values of red blood cell count and higher in white blood cell count of infected animals in the control group.