Equine Pasture Asthma in Brazil

Liana Villela de Gouvêa, Camila Bernardes, Michel José Sales Abdalla Helayel, Nayro Xavier de Alencar, Maria Fernanda Mello Costa, Daniel Augusto Barroso Lessa

Abstract


Background: Summer Pasture Associated Obstructive Pulmonary Disease (SPAOPD), or Equine Pasture Asthma (EPA), as termed by Ferrari et al. [17], has been described as an environmentally-induced respiratory disease that occurs during the warmer and more humid months, leading to reversible airway obstruction, persistent and non-specific airway hyper-responsiveness, and chronic neutrophilic airway inflammation. Exacerbation of clinical signs vary according to warm seasons, and range from mild to severe episodes of wheezing, coughing, and laboured breathing in a chronic state that is debilitating for the equine [4]. This report describes two cases of Equine Pasture Asthma that show clinical and environmental similarities with Summer Pasture Associated Obstructive Pulmonary Disease.

Case: The patients were crossbreed geldings that have never been stabled and were used for cattle management in a farm in southeastern Brazil. They presented poor performance and a persistent cough for over 3 years. Initially, the respiratory signs were only observed after exercise but, over the years, it gradually progressed to being observed when the horses were at rest. Both animals had a history of regular deworming and were previously treated by other veterinarians with antibiotics, clenbuterol, and mucokinetics. Little improvement was noticed by the owner and the signs returned over time as treatment was often discontinued. Clinical findings were compatible with the grade 3 mucus classification of Gerber et al. [18] as well as with score 2 for Severe Asthma of Davis and Sheats [13]. BALF cytology was done following the technique described by Couetil et al. [10]. Animal 1 presented slides with free yeast; macrophages and mucus with Curschmann’s spiral and counting of 29,7% of neutrophils (NE), 43,7% of lymphocytes (LP), 25,3% of macrophages (MC) and 1,3% of eosinophils (EO). Animal 2 presented slides with phagocytized yeast, mucus and counting of 27% of NE, 38,5% of LP, 33% of MC and 1,5% of EO.

Discussion: Diagnostic findings fit the clinical score 2 (from 0 to 3) for Severe Asthma [13], where the animal presented frequent cough with periods of no coughing, nostrils flares in inspiration and exhalation, obvious abdominal flattening and “heave line”, pulmonary auscultation with crackles, and scarce mucous nasal discharge. The cytological findings of our reported cases also falls within the Severe Asthma classification [13], when the specific counting of 300 cells is equivalent to ≥20% of neutrophils on BALF analysis and the animal present increase in respiratory rate/effort at rest. Similar counts were found by Costa et al. [9] counting 200 cells, Rossi et al. [28] also counting 300 cells, and Couetil and Thompson [11] counting 5 fields (of at least 100 cells) on a cytocentrifuge smear. The present report took place in a region of the Rio de Janeiro State, southeastern Brazil, which shows predisposing climatic characteristics similar to those described in previous SPAOPD reports. Yet, this very climate remains somewhat constant throughout the year, as seasonality in the Rio de Janeiro State is not as marked as in the Northern Hemisphere. Given this contrasting aspect, we believe that the term Equine Pasture Asthma, instead of SPAOPD, is more appropriate to describe the cases presented here. Also, to the best of the authors’ knowledge, this is the first documented description in Brazil of Equine Pasture Asthma in animals that were never stabled or fed with hay. This documented evidence of a chronic respiratory condition consistent with Equine Pasture Asthma but little related to seasonal changes presents as a warning to other possible cases that might be unnoticed in equine herds in Brazil and in similar climates.

Full Text:

PDF

References


Amaral P.C., Graça F.A.S., Vianna L.F.C.G., Borges J.R.J., Ferreira A.M., Pires N.R. & Voss C. 1999. Chronic obstructive pulmonary disease in horses of Military Police of Rio de Janeiro State. Revista Brasileira de Ciência Veterinária. 6(2):77-83.

Beech, J. 1975. Cytology of tracheobronchial aspirates in horses. Veterinary Pathology. 12(3):157-164.

Bond S., Léguillette R., Richard E.A., Couetil L., Lavoie J.P., Martin J.G. & Pirie R.S. 2018. Equine asthma: Integrative biologic relevance of a recently proposed nomenclature. Journal of Veterinary Internal Medicine. 32:2088-2098.

Bright L.A., Dittmar W., Nanduri B., McCarthy F.M., Mujahid N., Costa L.R., Burgess S.C. & Swiderski C.E. 2019. Modeling the pasture-associated severe equine asthma bronchoalveolar lavage fluid proteome identifies molecular events mediating neutrophilic airway inflammation. Veterinary Medicine: Research and Reports. 10:43-63.

Bullone M., Murcia R.Y. & Lavoie J.P. 2016. Environmental heat and airborne pollen concentration are associated with increased asthma severity in horses. Equine Veterinary Journal. 48:479-484.

Calder P.C. 2006. n-3 Polyunsaturated fatty acids, inflammation, and inflammatory diseases. The American Journal of Clinical Nutrition. 83(6): 1505S-1519S.

Costa L.R.R., Johnson J.R., Baur M.E. & Beadle R.E. 2006. Temporal clinical exacerbation of summer pasture-associated recurrent airway obstruction and relationship with climate and aeroallergens in horses. American Journal of Veterinary Research. 67(9):1635-1642.

Costa L.R.R., Johnson J.R. & Swiderski C.H. 2016. Managing Summer Pasture-Associated Obstructive Pulmonary Disease, an Asthma-like Disease of Horses. The American Association of Equine Practitioners. [Editorial]. Disponível em: . Acessado em 05/2020.

Costa L.R.R., Seahorn T.L., Moore R.M., Taylor H.W., Gaunt S.D. & Beadle R.E. 2000. Correlation of clinical score, intrapleural pressure, cytologic findings of bronchoalveolar fluid, and histopathologic lesions of pulmonary tissue in horses with summer pasture-associated obstructive pulmonary disease. American Journal of Veterinary Research. 61(2):167-173.

Couetil L.L., Cardwell J.M., Gerber V., Lavoie J.P., Léguillette R. & Richard E.A. 2016. Inflammatory Airway Disease of horses: revised Consensus Statement. Journal of Veterinary Internal Medicine. 30:503-515.

Couetil L.L. & Thompson C.A. 2020. Airway diagnostics. Veterinary Clinics of North America: Equine Practice. 36(1):87-103.

Davis E. & Rush B.R. Respiratory disease in the geriatric equine patient. 2006. In: Bertone J. (Ed). Equine Geriatric Medicine and Surgery. St. Louis: Saunders Elsevier, pp. 179-192.

Davis K.U. & Sheats M.K. 2019. Bronchoalveolar lavage cytology characteristics and seasonal changes in a herd of pastured teaching horses. Frontiers in Veterinary Science. 6:74.

Dixon P.M. & McGorum B. 1990. Pasture associated seasonal respiratory disease in 2 horses. Veterinary Record. 126(1):9-12.

Freeman K.P. & Roszel J.F. 1997. Equine cytology patterns in respiratory conditions of noninfectious or unknown origin. Compendium on Continuing Education for the Practising Veterinarian - North American Edition. 19(6):755-763.

Fernandes W.R., Morr E., Lopes L.C.L.C. & Baccarin R.Y.A. 2006. Estudo retrospectivo de 26 casos clínicos de obstrução aérea recorrente (OAR) em cavalos (1997-2004). Veterinária e Zootecnia. 13(2):173-181.

Ferrari C.R., Cooley J., Mujahid N., Costa L.R., Wills R.W., Johnson M.E. & Swiderski C.E. 2017. Horses with pasture asthma have airway remodeling that is characteristic of human asthma. Veterinary Pathology. 55(1):144-158.

Gerber V., Straub R., Marti E., Hauptman J., Herholz C., King M., Imhof A., Tahon L. & Robinson N.E. 2004. Endoscopic scoring of mucus quantity and quality: observer and horse variance and relationship to inflammation, mucus viscoelasticity and volume. Equine Veterinary Journal. 36(7):576-582.

Hewson J. & Viel L. 2002. Sampling, microbiology and cytology of the respiratory tract. In: Lekeux P. (Ed). Equine Respiratory Diseases. Ithaca: International Veterinary Information Service, pp. 1-12.

Kang J.X. & Weylandt K.H. 2008. Modulation of inflammatory cytokines by omega-3 fatty acids. In: Quinn P.J. & Wang X. (Eds). Lipids in Health and Disease. Netherlands: Springer, pp. 133-143.

Lessa D.A.B., Machado C.H., Duarte C.S., Wachholz L., Lima J.R.P.A. & Fernandes W.R. 2005. Lower respiratory tract diseases in riding horses in Rio de Janeiro: prevalence, clinical and laboratory aspects. Revista Brasileira de Ciência Veterinária. 12(1-3):77-83.

Lessa D.A.B., Mori E., Viana E.B., Santos O.J., Moreira J.F.E. & Fernandes W.R. 2007. Lavado broncoalveolar em eqüinos: revisão de literatura parte 2: achados citológicos. Arquivos de Ciências Veterinárias e Zoologia da UNIPAR. 10(1):31-38.

Mair T.S. 1996. Obstructive pulmonary disease in 18 horses at summer pasture. Veterinary Record. 138:89-91.

Marinkovic D., Aleksic‐Kovacevic S. & Plamenac P. 2007. Cellular basis of chronic obstructive pulmonary disease in horses. International Review of Cytology. 257:213-247.

McGorum B.C. & Dixon P.M. 1999. Summer pasture associated obstructive pulmonary disease (SPAOPD): an update. Equine Veterinary Education. 11:121-123.

Nogradi N., Couetil L.L., Messick J., Stochelski M.A. & Burgess J.R. 2015. Omega-3 fatty acid supplementation provides an additional benefit to a low-dust diet in the management of horses with chronic Lower Airway Inflammatory Disease. Journal of Veterinary Internal Medicine. 29:299-306.

Pirie R.S., Couetil L.L., Robinson N.E. & Lavoie J.P. 2016. Equine asthma: An appropriate, translational and comprehendible terminology? Equine Veterinary Journal. 48:403-405.

Rossi H., Virtala A.M., Raekallio M., Rahkonen E., Rajamäki M.M. & Mykkänen A. 2018. Comparison of tracheal wash and bronchoalveolar lavage cytology in 154 horses with and without respiratory signs in a referral hospital over 2009−2015. Frontiers in Veterinary Science. 5:61.

Rush B. & Mair T. 2004. Non-infectious pulmonary diseases and diagnostic techniques. In: Rush B. & Mair T. (Eds). Equine Respiratory Diseases. Oxford: Blackwell Science Ltd., pp. 187-232.

Seahorn T.L., Groves M.G., Harrington K.S. & Beadle R.E. 1996. Chronic obstructive pulmonary disease in horses in Louisiana. Journal of the American Veterinary Medical Association. 208(2):248-251.

WeatherSpark. 2020. Cedar Lake Ventures Inc. Average Weather in Rio Bonito. 2020. Disponível em: . Acessado em 05/2020.

Zinkl J.G. 2002. Lower respiratory tract. In: Cowel R.L. & Tyler R.D. (Eds). Diagnostic Cytology and Hematology of the Horse. St Louis: Mosby, pp. 73-86.




DOI: https://doi.org/10.22456/1679-9216.107923

Copyright (c) 2021 Liana Villela de Gouvêa, Camila Bernardes, Michel José Sales Abdala Helayel, Nayro Xavier de Alencar, Maria Fernanda Melo Costa, Daniel Augusto Barroso Lessa

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.