Prevalence of Upper Respiratory Tract Disorders Detected with a Flexible Videoendoscope in Thoroughbred Racehorses.

Mineral supplement with pre- and probiotic improves respiratory immune status in yearling racing Thoroughbred horses: preliminary results

“…PLH usually develop in the young horse as an immune reaction to inhaled particles from the new environment, and are expected to disappear by the age of six years due to the maturity of the immune system (HOBO et al, 1995). Interestingly, in a previous study of our group (ALMEIDA, 2015), PLH was significantly reduced just one year after stabling, in comparison with the preliminary examinations.…”

Effect of Laryngeal Hemiplegia of Thoroughbred Racehorses on Racing Performance and the Usefulness of Laryngoplasty Performed on Horses with Laryngeal Hemiplegia

“…The upper respiratory tracts of horses were endoscopically examined [6] and the degree of LH was graded according to the criteria described by Rakestraw et al [10]: Grade 0-synchronous full abduction and adduction of the left and right arytenoids cartilages; Grade I-asynchronous movement (hesitation, flutter, adduction weakness) of the left arytenoids cartilage during any phase of respiration. Full abduction of the left arytenoids cartilage (as compared to the right) inducible by nasal occlusion or swallowing; Grade IIasynchronous movement (hesitation, flutter, adductor weakness) of the left arytenoids cartilage during any phase of respiration.…”

“…Roaring, abnormal respiratory noise during training or racing, is associated with obstructive disease of the upper respiratory tract, including laryngeal hemiplegia (LH), and is associated with poor performance [3,5,6,8,10,11]. When LH grade of thoroughbred racehorses is severe, the corniculate process of the arytenoid cartilage adducts during inspiration and can severely obstruct the airway, greatly reducing race performance [8].…”

“…When LH grade of thoroughbred racehorses is severe, the corniculate process of the arytenoid cartilage adducts during inspiration and can severely obstruct the airway, greatly reducing race performance [8]. It is reported that is the prevalence of LH in thoroughbred racehorses is 2-8% [5,6,11].…”

Estimation of Heritability of Laryngeal Hemiplegia in the Thoroughbred Horse by Gibbs Sampling

“…As mentioned above, the LH-grades consisted of five severity classes going from 0 to 4 (Hackett et al 1991;Hobo et al 1995). Racehorse breeders are often interested in whether a genetic effect controlling a complex disorder is present in the population.…”