358


EQUINE VETERINARY EDUCATION / AE / july 2022


Percentage Profiles Chart Average 34% 66%


Positive Negative


57% TCC 43%


30% Mucus 70%


30% Eos 70%


20% Neut 80% 0% 20% 40% 60% 80% Fig 1: Relative values for each test results and the average of all criteria for EAS-positive and EAS-negative horses.


Although there are previous reports of BALF collection


post-exercise to demonstrate that exercise itself does not cause airway inflammation (Clark et al. 1995), there are not many studies involving cytological examination of BALF after a standardised exercise test. To our knowledge, this is the first report of BALF cytology post-exercise in Brazilian pacers. Our results demonstrate that post-exercise BALF cytology can be a valuable tool for diagnosing EAS in subclinical cases. From all the diagnostic criteria used, the only one common to all horses was total cell count in the BALF, suggesting that in post-exercise BALF this criterion might be the most sensitive one for identifying subclinical EAS. During this research, horses were subjected to a


standardised exercise test (SET) in the field inspired by the work these breeds of horses perform during competition. Other SET might not be appropriate since they would impose metabolic and musculoskeletal demands very different than those sustained by Brazilian pacers. It is the view of the authors that modality-specific SETs should be employed whenever possible. Other equestrian modalities and authors share similar views (Art et al. 1990; Barbesgaard et al. 2010; Munsters et al. 2014). A fixed speed for the SET was not determined since there


is large variation in the speed pacers can achieve within their morphologic configuration. Previous studies have shown pacing speeds for MM to vary greatly and be largely individual (Lage et al. 2017). We considered sufficient a


© 2021 EVJ Ltd


movement pattern that was quick, between 12 and 14 km/h, similar to what is seen during competition, especially considering these breeds use mostly aerobic metabolism (Wanderley et al. 2010). The endoscopic evaluation was conducted 30 min after


exercise in order to allow for animals to fully recover from the SET and return to baseline heart rate and respiratory rate for sedation to be carried out with minimal complications. The possible detection of exercise-induced pulmonary haemorrhage (EPIH), should that be a feature, was also taken into consideration when deciding the time of post-exercise endoscopy. Thirty minutes post-exercise is considered to be the minimum amount of time required for EIPH to be consistently detected (Hinchcliff et al. 2014). Low-grade EIPH was in fact detected in three animals (data not shown), but evaluation of degree through cytology using a total haemosiderin score was not conducted due to its impracticality in a field setting. Due to the importance of respiratory diseases to equine


health and welfare, diagnostic criteria helping clinicians identify subclinical and clinical illness are of paramount importance. In this sense, the phenotypic characterisation of EAS by the Asthma Consensus (Cou€


etil et al. 2016) is a


hallmark for equine clinicians worldwide. However, the publication did not clarify cut-off values for differentiation between mild EAS and moderate EAS, with horses classified as severe presenting neutrophilia above 25% in the BALF. In


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88