Upper respiratory tract (URT) examination in italian Lipizzaner breed: frequency of pharyngeal lymphoid hyperplasia (PLH), recurrent laryngeal neuropathy (RLN), bacterial infections and presence of equine herpesviruses type 1 and 4 (EHV 1-4).

The aim of this study was to investigate, in a population limited and managed in a uniform manner, the presence, prevalence, and severity of PLH and RLN also trying to establish a possible relationship with bacterial infections and the presence of equine herpesvirus type 1 and 4. The population of the Lipizzaner breeding stud of Monte Romano (RM) was then subjected to video-endoscopic investigation, nasopharyngeal swabs (TNF) and blood samples were performed, to be used for bacteriological, virological and serological analysis. The endoscopic examination, conducted over a period of three years, collected a total of 195 observations while the searching for EHV-1 and 4 was conducted on a sample stratified by gender selecting 31 females and 24 males from 134 animals during the first year during which nasopharyngeal swabs were made. The results of this study would support the exclusion of bacterial or viral causes and confirm, a heritability for PLH that seems more evident in the forms found in adults. Recurrent laryngeal neuropathy, without consider degree, it was notice more in male; genetic analyses showed no heritability. There was no correlation between degree of PLH and the presence of RLN.