Laboratory findings in respiratory fluids of the poorly-performing horse.

Any disorder impairing a performance horse's ability to ventilate its lungs and exchange oxygen compromises exercise performance in any discipline. Since bronchoalveolar lavage was described in horses in the early 1980s, laboratory evaluation of respiratory fluids, along with clinical and functional assessment of the respiratory system, has become a relevant step in the diagnosis of respiratory disease affecting performance. The aim of this review is to provide objective information to assist clinicians in interpreting laboratory findings by (1) summarising published cytological references values in both clinically healthy horses and those with various airway diseases, (2) assessing the influence of physiological circumstances, such as exercise, on the cytological evaluation, (3) discussing the relationship between cytological and microbiological analyses, clinical signs and respiratory function, and (4) suggesting how this latter relationship may affect performance.

Sub-clinical diseases affecting performance in Standardbred trotters: diagnostic methods and predictive parameters.

The objectives of this study were to determine the prevalence of sub-clinical diseases in poorly-performing Standardbred horses, compare their physiological response to exercise with control horses, and identify predictive parameters of poor-performance. Fifty horses underwent thorough clinical and ancillary examinations, including haematological and biochemical evaluation, Doppler echocardiography, standardised exercise tests (SETs) on both treadmill and racetrack, treadmill video-endoscopy and collection of respiratory fluids. Most of the poorly-performing horses exhibited many concomitant diseases. The most frequently diagnosed problems involved the lower and upper respiratory tract and the musculoskeletal system. Poor-performers had lower speeds at a blood lactate (LA) concentration of 4mmol/L (V(LA4)) and a heart rate (HR) of 200bpm (V(200)) on treadmill and racetrack, as well as lower values for haematological parameters, plasma angiotensin-converting enzyme and antioxidants, compared to control horses. Problems of the respiratory system were the most frequently diagnosed sub-clinical diseases affecting performance. SETs, together with some blood markers, may be useful as a non-specific diagnostic tool for early detection of diseases that may affect performance.