Elevated Serum Cardiac Troponin I in Cattle with Theileriosis

Background T heileria annulata is a blood parasite affecting ruminants. Hemolytic anemia, secondary hypoxia, and vasculitis are the most important features of tropical theileriosis. Objectives Evaluation of electrocardiographic findings and changes in cardiovascular biochemical markers including cTnI concentrations in cattle naturally infected with theileriosis in the absence of acute cardiac failure. Animals Ninety adult H olstein cattle (>1 year) with clinical and laboratory evidence of theileriosis and 30 healthy cattle served as controls. Methods Case‐control study in which blood samples were collected and randomized after clinical, hematologic, parasitologic examination and laboratory confirmation and electrocardiographic recording on all animals, serum cardiac troponin I (cTnI), aspartate aminotransferase ( AST ), and creatine kinase‐ MB ( CK ‐ MB ) were evaluated. Results Serum concentration of cTnI was significantly higher in cattle with theileriosis (mean: 0.028 ng/mL; range: 0.005–0.21 ng/mL; control mean: 0.011; range: <0.005–0.09 ng/mL; P  = .003). There was significant correlation between serum level of cTnI and PCV ( r  = −0.257; P  < .001) and also between cTnI and parasitemia ( r  = 0.515; P  < .001). Mean serum activities of AST and CK ‐ MB were 107 ± 46 and 301 ± 103 U/L in sick animals, which were significantly higher than healthy cattle ( P  = .002 and P  = .041, respectively). There were no pathologic arrhythmias detected in sick animals. Conclusions and Clinical Importance Theileriosis is a risk factor for elevation of cardiac biomarkers in naturally infected H olstein cattle. Severity of anemia and parasitemia might contribute to the pathophysiology of myocardial damage. The prognostic significance of increased serum cardiac troponin I concentrations in cattle with hemolytic anemia merits further investigation.