Bronchoalveolar lavage hemosiderosis in lightly active or sedentary horses.

BACKGROUND: Hemosiderophages in bronchoalveolar lavage fluid (BALF) are commonly ascribed to exercise-induced pulmonary hemorrhage (EIPH). Little information exists regarding the presence of these cells in horses that perform light or no work and that are referred for respiratory problems. OBJECTIVES: Evaluate the presence of hemosiderophages in BALF of horses suspected of respiratory disease without history of or risk factors for EIPH and determine predictors of hemosiderophages in BALF in this population. METHODS: Observational retrospective cross-sectional study using STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Bronchoalveolar lavage fluid cytology reports of 353 horses evaluated for respiratory disease between 2012 and 2022 at the Cummings School for Veterinary Medicine were reviewed retrospectively. Horses with a history or likelihood of having performed past strenuous exercise were removed, and the remaining 91 horses were divided into hemosiderin-positive (HSD-POS) and hemosiderin-negative groups based on Perls' Prussian blue staining. Potential predictors for the presence of hemosiderophages in BALF (history, clinical evaluation, baseline lung function, airway reactivity, BALF cytology, and hemosiderin score) were compared between the 2 groups, using univariate and multivariate analyses. RESULTS: Horses with a diagnosis of severe equine asthma (sEA; odds ratio, 11.1; 95% confidence interval, 3.2-38.5; P < .001) were significantly more likely to be HSD-POS than horses with mild-to-moderate equine asthma. CONCLUSIONS AND CLINICAL IMPORTANCE: Hemosiderophages were found in the BALF cytology in a subset of horses that perform light or no work and presented for respiratory signs; these cells were found more frequently in horses with sEA. The link between hemosiderophages and sEA highlights previously unstudied pathology associated with this common disease.

A CONSORT-guided, randomized, double-blind, controlled pilot clinical trial of inhaled lidocaine for the treatment of equine asthma.

There are limited options for treatment of the common disease, equine asthma. The aim of this study was to estimate the feasibility and potential efficacy of using nebulized lidocaine for treating equine asthma, while at the same time treating a separate cohort of asthmatic horses with inhaled budesonide. Nineteen horses with a history consistent with equine asthma were recruited from our referral population for a double-blind, randomized, controlled pilot clinical trial using Consolidated Standards of Reporting Trials (CONSORT) guidelines. After screening, 16 horses met the inclusion criteria for equine asthma and 13 horses actually completed the study. Horses were treated by their owners at home for 14 d before returning to our hospital for follow-up assessment. Interventions consisted of nebulization q12h for 14 d with 1.0 mg/kg body weight (BW) of lidocaine or corticosteroid treatment (nebulized budesonide 1 µg/kg, q12h). Clinical and tracheal mucus score, pulmonary function testing, and respiratory secretion cytology were assessed after 2 weeks of treatment to determine the outcome. Both lidocaine and budesonide cohorts had significant decreases (P < 0.05) in clinical score; the lidocaine cohort showed a significant decrease in bronchoalveolar lavage (BAL) neutrophil percentage and tracheal mucus score. Neither treatment resulted in significant changes in lung function parameters. No adverse events occurred. Lidocaine may be an effective and safe treatment for equine asthma in horses that cannot tolerate treatment with corticosteroids.

Il existe des options limitées pour le traitement de la maladie répandue, l'asthme équin. Le but de cette étude était d'estimer la faisabilité et l'efficacité potentielle de l'utilisation de la lidocaïne nébulisée pour traiter l'asthme équin, tout en traitant en même temps une cohorte distincte de chevaux asthmatiques avec du budésonide inhalé. Dix-neuf chevaux ayant des antécédents compatibles avec l'asthme équin ont été recrutés dans notre population de référence pour un essai clinique pilote contrôlé, randomisé, en double aveugle, conformément aux directives CONSORT (Consolidated Standards of Reporting Trials). Après dépistage, 16 chevaux répondaient aux critères d'inclusion de l'asthme équin et 13 chevaux ont terminé l'étude. Les chevaux ont été traités par leurs propriétaires à domicile pendant 14 jours avant de retourner à notre hôpital pour une évaluation de suivi. Les interventions consistaient en une nébulisation deux fois par jour pendant 14 jours avec 1,0 mg/kg de poids corporel (PC) de lidocaïne ou un traitement aux corticostéroïdes (budésonide nébulisé 1 µg/kg, q12h). Le score clinique et de mucus trachéal, les tests de la fonction pulmonaire et la cytologie des sécrétions respiratoires ont été évalués après 2 semaines de traitement pour déterminer le résultat. Les cohortes de lidocaïne et de budésonide présentaient des diminutions significatives (P < 0,05) du score clinique; la cohorte de lidocaïne a montré une diminution significative du pourcentage de neutrophiles du lavage bronchoalvéolaire (BAL) et du score de mucus trachéal. Aucun des deux traitements n'a entraîné de changements significatifs dans les paramètres de la fonction pulmonaire. Aucun événement indésirable n'est survenu. La lidocaïne peut être un traitement efficace et sûr de l'asthme équin chez les chevaux qui ne tolèrent pas le traitement aux corticostéroïdes.(Traduit par Docteur Serge Messier).