Endoscopic findings, microbiological and cytological evaluation of tracheal aspirates in a population of Standardbred horses with poor performances

Abstract

Sixty-two Standardbred horses housed at the same racetrack, with history of reduced exercise tolerance, cough lasting for at least two weeks and/or prolonged recovery time were clinically examined. An endoscopic examination of the nasopharynx, larynx and trachea to the level of the carina was performed, amount of mucus in trachea was registered and samples of tracheal wash for cytological and microbiological examinations was collected. A strong statistical association between amount of mucus in trachea and neutrophils percentage in tracheal wash was found. Bacteria isolated included Streptococcus equi subsp. zooepidemicus (14 horses), Streptococcus pneumoniae (four horses), S. mutans (four horses), S. equinus (four horses) and Burkholderia cepacia (10 horses). S. zooepidemicus and S. pneumoniae were associated with elevated amount of mucus and increased neutrophilic percentage. B. cepacia was associated with cytological evidence of haemosiderophages but its role in racehorses needs further investigations. Mycoplasma spp. and Pasteurella spp. have not been isolated, suggesting that, as for the other putative causes of inflammatory airway diseases, infection could have a regional distribution among horse populations. This study shows that various types of airway inflammations exist in the examined population and that S. zooepidemicus and S. pneumoniae could play an important role in etiopathogenesis of airway inflammation in some horses. Particulate matter, pro-inflammatory agents or noxious gases present in the stables or on the track matter, could be the cause of inflammation in non infected horses.

Investigation of the presence of Mycoplasma as an etiologic agent of inflammatory airway diseases in thoroughbred racehorses in İstanbul Province

“…The samples were submitted to the İstanbul Race Horse Hospital along with complaints of poor performance and/ or abnormal respiratory sounds at rest or while training. The same clinician evaluated the clinical signs of the horses, and the amount of tracheal mucus accumulation (classified as none, little, intermediate, or high), poor performance, coughing at rest or during exercise, and nasal discharge were recorded while collecting samples from the horses (2,5,(16)(17)(18). The sex, age, and strain (English or Arabian thoroughbred) of the horses were also recorded.…”

Usefulness of the assessment of discharge accumulation in the lower airways and tracheal septum thickening in the differential diagnosis of recurrent airway obstruction (RAO) and inflammatory airway disease (IAD) in the horse

“…This disease can affect horses at any age, and similarly to RAO, there are no sex or breed predilections. To this day, the aetiology is not known, but infectious agents and allergens are not excluded (Laus et al 2009). To diagnose IAD, broncho-alveolar lavage should be performed, where three different cytological patterns are described.…”

Safkan İngiliz ve Arap Yarış Atlarında Görülen Beta Hemolitik Streptococcus Türlerinin Sitolojik Bulgular Eşliğinde Çeşitli Vücut Bölgelerinden İzolasyonu ve Antibiyotik Duyarlılıkları

“…Nasal swabs were not included to the study due to high content of beta hemolytic streptococci and other bacterial agents as normal flora of upper airways in horses [2,16] . Tracheal wash samples were collected according to the previous study [18] . Briefly, 40 mL sterile physiologic saline solution was instilled from proximal trachea and immediately aspirated back to a 60 mL sterile injector with a flushing catheter elongated via the biopsy channel of the endoscopy.…”

“…The air dried slides were stained with May Grunwald Quick stain (Bio Optica 20134 Milano Italy) that was used according to the manufacturer's instructions. The slides were examined under 100x magnification microscope and percentage (%) of the neutrophils, macrophages, lymphocytes, eosinophils and mast cells were determined by counting 300 cells [18] . Inflammation of the lower airways was considered positive when neutrophils made up ≥30% of all cells and the presence of degeneration in neutrophils and likely to have intracellular bacteria (Fig.…”

“…Besides the isolation of a microorganism from clinical samples, determining the inflammation by cytological examination in concordance with bacterial isolation is also detrimental in order to separate contamination from real infection in the diagnosis of bacterial infections [17,18] .…”