Association of myocardial parasitic load with cardiac biomarkers and other selected variables in 10 dogs with advanced Canine Leishmaniasis

Abstract

Background: The association between myocardial parasitic load (MPL) and cardiac biomarkers in Canine Leishmaniasis (CanL) has not been studied.

Methods: Dogs with advanced CanL were prospectively recruited and were included if they were euthanised. Prior to euthanasia these variables were assessed: hematocrit, globulin, creatinine, N-terminal-pro brain natriuretic peptide (NT-proBNP), cardiac troponin I (cTnI), blood pressure, urine protein/creatinine ratio and echocardiographic parameters. A left ventricular (LV) sample was taken for histopathology and MPL evaluation by quantitative PCR. Correlation of MPL with all variables was analysed. Dogs with lower and higher histopathology scores were compared.

Results: Ten dogs were included. NT-proBNP was 6946 pmol/ (interquartile range [IQR] 3751-9268 pmol/L) and cTnI 4.56 ng/mL (IQR 0.46-13.1 ng/mL). In all dogs, echocardiography showed an increase in LV thickening, and histopathology revealed moderate to severe lympho-plasmocytic myocarditis and/or myocardial cell degeneration. MPL was 215.53 parasites/gram (IQR 21.2-1372.63 parasites/gram). A strong correlation (p < 0.001; R = 0.90; R² 0.81) with cTnI was observed but correlation with any of the other variables or differences between the two histopathological scores, were not detected.

Conclusions: MPL in dogs with advanced CanL shows variable but generally high levels. A strong association between MPL and cTnI was observed, which encourages the exploration of cTnI as a marker in CanL.