Effects of Breed, Exercise, and a Two-Month Training Period on NT-proBNP-Levels in Athletic Dogs

N-terminal pro-b-type natriuretic peptide (NTproBNP) is a cardiac biomarker used to detect myocardial wall stress. Physical activity and cardiac disease can affect serum NTproBNP concentrations. In people, different types of physical activity have different effects on NTproBNP. Our hypothesis was that physical activity and training have an effect on NTproBNP concentrations depending on the type of exercise and the intensity. Seven German Shepherd dogs (GSD) under military training performing short bursts of fast-paced interval exercise and seven Eurohounds (EHs) training for racing competition with endurance exercise were included in the study. Blood samples were taken at enrollment (T0) and after a two-month (T2mth) training period; on both occasions, the samples were acquired before and after physical exercise. An echocardiographic evaluation was performed at T0. Echocardiographic heart size was larger in the EHs compared to the GSDs. The NTproBNP concentration was higher in the EHs than in the GSDs before and after exercise at T0 and T2mth. Echocardiographic parameters of heart size and wall thickness correlated with NTproBNP at T0 before and after exercise. Exercise induced an elevation of NTproBNP in the EHs at T0 and T2mth, while in the GSDs this was observed only at T0. In the EHs, post exercise was associated with higher NTproBNP at T2mth compared to T0, while in the GSDs the opposite pattern was noticed. From our study, the serum NTproBNP concentration differs between breeds. Intense physical activity causes an increase in NTproBNP. A two-month training period does not affect the NTproBNP concentration at rest. Intense physical activity may increase NTproBNP above the reference range in individual dogs.