Introduction
India has few unique horse breeds, which survived in its harshest environment for and has a history of usage over several thousand years as pack animals, war, local transport, agriculture and religious ceremonies. Kathiawari horses are culturally important animals in India and has a very rich heritage and is one of the breed with excellent endurance capabilities In general, the cardiovascular problems in horses can cause poor performance and sudden death during high-intensity exercises. Thorough cardiac examination is more important for assessing the performance of heart and diagnosing cardiovascular dysfunctions in horses (Chanda and Petchdee, 2022). Cardiac troponin I (cTnI) and cardiac troponin T (cTnT) are the specific cardiac biomarkers for diagnosing the cardiac injuries in horses. These biomarkers are more effective in identifying cardiac injuries due to various conditions such as infection, trauma, ischemia, toxicity, inflammation, or autoimmune disorders thus paving the way to extend their clinical use in equine cardiology (Lippi and Plebani, 2019). Use of these biomarkers shall be seen as a new revolution in the diagnosis of heart diseases especially when assayed with the novel high-sensitivity immunoassays, which enables the detection of even trace amounts of both cTnI and cTnT in the vast majority of healthy individuals (van der Linden et al ., 2017).
The exercise induced increases in cTnI is mild and not comparable to the concentrations found in the horses with signs of cardiac disease. The increased concentrations of cTnI along with the clinical symptoms and findings on ECG, echocardiography and necropsy indicate that the assay is used to detect horses with cardiac disease. Pronounced elevation in cardiac troponin I (cTnI) concentration could be a robust indicator of myocardial injury (Nostell and Häggström, 2008).
Echocardiography is very useful for investigation of cardiac structures and determination of the chamber size provides valuable information about the cardiac function. Echocardiographic examination is a fundamental tool for identifying and interpreting abnormal findings in healthy horses. Normal reference ranges for several echocardiographic measurements have been reported for Thoroughbreds, Standardbreds, Warmbloods and Arabian Thoroughbreds. Up to now, no echocardiographic reference values have been reported for Indian breeds like Kathiawari and Marwari horses. Based on this aim the study was undertaken in Indian Kathiawari horses.