Steamed hay and alfalfa pellets for the management of severe equine asthma.

BACKGROUND: Steaming hay significantly reduces respirable particles and provides a palatable alternative to dry hay for horses with asthma, but there are few prospective studies demonstrating the clinical efficacy of steamed hay. OBJECTIVES: To compare the efficacy of alfalfa pellets and steamed hay in improving lung function and inflammation of horses with severe asthma (SEA). STUDY DESIGN: Controlled crossover study. METHODS: Ten horses with SEA were enrolled and nine completed the study. Horses were housed indoors and fed hay. Once in exacerbation, they were fed pellets and steamed hay for 4 weeks, in a crossover design. Weighted clinical scores and lung function were recorded weekly. Bronchoalveolar lavage fluid (BALF) cytology and mucus scores were recorded before and after each diet. RESULTS: Based on linear mixed model (LMM) analysis, weighted clinical scores significantly improved over time (p < 0.001, no diet effect or time-diet interactions). With pellets, weighted clinical scores decreased from (median (interquartile range)) 13 (5.5) to 2 (1.5), while with steamed hay, they decreased from 10 (9.5) to 6 (8.5). With pellets, lung resistance decreased significantly from a baseline of (mean (SD)) 2.62 (0.77) cmH2O/L/s to 1.17 (0.66), 0.79 (0.54), 0.70 (0.20), 0.62 (0.18) on Weeks 1-4, respectively (LMM with post hoc tests, p < 0.001). With steamed hay, the resistance decreased significantly from a baseline of 2.34 (0.93) cmH2O/L/s to 1.38 (0.49) and 1.51 (0.66) on Weeks 1 and 2, respectively (p < 0.03). Neutrophils BALF decreased significantly with both diets (pellets: 40.2 (24.4) to 20.1 (11.0) %; steamed hay 30.9 (20.2) to 25.7 (17.6) %; LMM, p = 0.006). MAIN LIMITATIONS: A small number of horses in a research setting. Dust was not measured in the stalls. CONCLUSIONS: Clinical scores, lung function and BALF inflammation of horses with SEA improved with steamed hay and pellets, but the effect on lung function was more pronounced with pellets.

Effects of soaked hay on lung function and airway inflammation in horses with severe asthma.

BACKGROUND: Reducing inhaled dust particles improves lung function in horses with severe asthma. Soaked hay is commonly used by owners, but its efficacy in improving lung function and inflammation has not been documented. OBJECTIVES: To measure the effects of soaked hay and alfalfa pellets in horses with severe asthma. ANIMALS: Ten adult horses with severe asthma from a research colony. METHODS: Prospective controlled trial. Horses in clinical exacerbation were housed indoors and allocated to be fed either soaked hay (n = 5) or alfalfa pellets (n = 5) for 6 weeks. Soaked hay was immersed for 45 minutes and dried out hay was discarded between meals. Pulmonary function and clinical scores were measured before and after 2, 4, and 6 weeks. Tracheal mucus scores and bronchoalveolar lavages were performed before and after 6 weeks. Lung function was analyzed with a linear mixed model using log-transformed data. RESULTS: Lung resistance decreased from (median (range)) 2.47 (1.54-3.95) to 1.59 (0.52-2.10) cmH2 O/L/s in the pellets group and from 1.89 (1.2-3.54) to 0.61 (0.42-2.08) cmH2 O/L/s in the soaked hay group over the 6-week period for an average difference of 1.06 cmH2 O/L/s for pellets (95% confidence interval [95% CI]: 0.09-2.04, P = .03, not significant after correction) and 1.31 cmH2 O/L/s for soaked hay (95% CI: -0.23 to 2.85, P < .001, significant). CONCLUSION AND CLINICAL IMPORTANCE: Soaked hay can control airway obstruction in horses with severe asthma. The strict protocol for soaking and discarding dried-out hay in this study could however be considered too great of an inconvenience by owners.

Use of Clinical Audits to Evaluate Timing of Preoperative Antimicrobials in Equine Surgery at a Veterinary Teaching Hospital.

Based on human surgical guidelines, intravenous antimicrobials are recommended to be administered within 60 min of surgical incision. Achieving this target in horses is reportedly challenging and influenced by hospital policies. The objectives of this study were to evaluate and improve: (1) the timing of antimicrobial administration to surgical incision (tAB-INC), (2) contributions of anesthesia pre-induction (tPRI) and surgical preparation (tPREP) periods to tAB-INC, and the (3) completeness of antimicrobial recording. Two clinical audits were conducted before and after the policy changes (patient preparation and anesthesia record keeping). tPRI, tPREP, and tAB-INC were calculated and compared for elective arthroscopies and emergency laparotomies within and between the audits. The percentage of procedures with a tAB-INC <60 min was calculated. Antimicrobial recording was classified as complete or incomplete. A median tAB-INC <60 min was achieved in laparotomies (audit 1; 45 min, audit 2; 53 min) with a shorter tPREP than arthroscopies (p < 0.0001, both audits). The percentage of procedures with tAB-INC <60 min, tAB-INC, tPRI, and tPREP durations did not improve between the audits. There was a positive correlation between the number of operated joints and tPREP (audit 1, p <0.001, r = 0.77; audit 2, p < 0.001, r = 0.59). Between audits, antimicrobial recording significantly improved for elective arthroscopies (82-97%, p = 0.008) but not emergency laparotomies (76-88%, p = 0.2). Clinical audits successfully quantified the impact of introduced changes and their adherence to antimicrobial prophylaxis guidelines. Antimicrobial recording was improved but further policy changes are required to achieve a tAB-INC <60 min for arthroscopies.