The prevalence of cardiac murmurs among standardbred racehorses presented with poor performance.

This research investigates the occurrence of heart murmurs in standardbred racehorses exhibiting poor performance. The study revealed that heart murmurs are commonly found in underperforming horses, with the tricuspid valve regurgitation being the most frequent type.

Research Methodology

• The research constituted a comprehensive diagnostic protocol on 752 Standardbred horses noted for poor performance results.
• Of these, 233 horses that demonstrated cardiac murmur symptoms were selected for further examination using echocardiography and color flow Doppler (CFD) mapping.
• These non-invasive imaging techniques provide an accurate representation of blood flow through the heart, helping to identify potential heart murmurs.

Research Findings

• The study identified murmurs of tricuspid valve regurgitation in 185 horses, making it the most common type observed in the sample.
• Heart murmurs involving other types of valve regurgitations: mitral (23), aortic (9), and pulmonary (3), were less frequent.
• Different timings of functional murmurs were also discovered, namely functional systolic (10), functional pre-systolic (11), and functional early diastolic (2).
• Two-dimensional and M-mode echocardiography, techniques used for imaging the structure and movement of heart components, did not detect abnormalities in 145 horses.
• However, the CFD mapping identified presence of one or more jets of valve regurgitation in 149 horses, which is a typical tell-tale sign of a heart murmur.

Conclusion

• The research suggests that cardiac murmurs are a common occurrence in Standardbred horses demonstrating poor performance.
• This finding emphasises the need for regular cardiovascular evaluations in racehorses to early detect and treat potential performance-limiting heart conditions.