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

SIMPLE SUMMARY: In people, different types of physical activity can induce various types of heart adaptation. These changes are not only associated with morphological and physiological consequences on the heart, but they are also accompanied by alterations in cardiac biomarkers. In dogs, these parameters are clinically used, but they have not been thoroughly evaluated in animals that are regularly engaged in high-level sporting activities. The aim of this paper was to describe the effects on a specific cardiac blood parameter due to the physical activity in two different breeds of dogs in their respective sports. Additionally, our study included the use of echocardiography and electrocardiography to further assess these parameters. Exercise induced different responses in the two groups, and the measured parameter correlated with certain echocardiographic values. Our findings suggest that the physical activity must be considered when evaluating this blood parameter in canine patients. Further studies are necessary to evaluate the utility of this biomarker to distinguish possible cardiac diseases from physiological athletic adaptations. ABSTRACT: 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 (T(0)) and after a two-month (T(2mth)) training period; on both occasions, the samples were acquired before and after physical exercise. An echocardiographic evaluation was performed at T(0). 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 T(0) and T(2mth). Echocardiographic parameters of heart size and wall thickness correlated with NTproBNP at T(0) before and after exercise. Exercise induced an elevation of NTproBNP in the EHs at T(0) and T(2mth), while in the GSDs this was observed only at T(0). In the EHs, post exercise was associated with higher NTproBNP at T(2mth) compared to T(0), 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.