Correlation between some haematological parameters, leukocyte ratios, parasitaemia and their prognostic value in canine trypanosomosis

Abstract

African trypanosomosis is a disease of high economic importance in animals and humans caused by an apicomplexan haemoparasite of the genus Trypanosoma. Canine trypanosomosis is relatively common in Nigeria because of the high prevalence of the insect vector. The haematology, erythrocyte, and serum sialic acid levels of dogs experimentally infected with Federe strain of Trypanosoma brucei brucei was studied in a total of five (5) 4-month old dogs. Three of the dogs were randomly selected and inoculated subcutaneously with 1 × 106 of T. brucei, while the remaining two dogs served as the uninfected control. The parasitaemia, packed cell volume (PCV), total and differential white blood cell count, erythrocyte surface sialic acid (ESSA) and free serum sialic acid (FSSA) were determined twice a week. The lymphocyte/monocyte ratio (LMR) and neutrophil/lymphocyte ratio (NLR) were calculated. The infected dogs had a significantly lower PCV, total white blood cell count (TWBC), LMR and ESSA compared to the uninfected control group. There was a strong positive correlation between NLR and PCV decrease, moderate negative correlation between LMR and PCV decrease, strong negative correlation between LMR and ESSA changes, and a moderate positive correlation between ESSA changes and parasitaemia. The higher NLR in trypanosome infection associated with decreasing levels of PCV indicates a poor prognosis, and NLR may be a useful tool in estimating trypanosomosis effect on PCV in dogs. Similarly, the moderate negative and strong negative correlations between LMR with decreases in PCV and ESSA respectively indicates poor prognosis in the response to trypanosomosis in dogs. Thus, NLR, LMR and ESSA levels can be used as markers for predicting disease outcome in trypanosome infection in dogs. This is, however, not the case with parasitaemia as the clinico-pathologic effect of trypanosomosis cannot be estimated from the level of parasitaemia alone.