Dogs infected with babesiosis have evidence of acute renal damage and cardiac dysfunction. Renal damage is characterised by the presence of renal tubular cells, proteinuria, and variable enzymuria and azotaemia. Causes of the renal damage are attributed to a combination of reduced glomerular filtration rate, anaemic hypoxia, and met-haemoglobin. Renal haemodynamics are also more likely to be abnormal when cardiac dysfunction is present, which in babesiosis appears to be associated with myocardial infarction. Cardiac dysfunction can be demonstrated by elevated serum cardiac troponins, cardiac histopathology, and ECG changes.