Clinical, endoscopic and mycological finding in horses with chronic nasal discharge

Subject Areas : Internal medicine of large animals

fereydoon rezazadeh ^{1 *} , فرزاد کتیرایی ² , , Mohammad Hassan , Mohammad Hassan Riyahi ³ , Hossein Kulivand Saluki ⁴

1 -
2 - استادیار قارچ شناسی دامپزشکی دانشگاه تبریز
3 - graduated of veterinary Medicine, Faculty of Veterinary Medicine, University of Tabriz, Tabriz- Iran. .
4 - DVM student of Veterinary Medicine, University of Tabriz, Tabriz- Iran. .

Received: 2025-03-11 Accepted : 2025-04-03 Published : 2025-04-10

Keywords: Keywords: Chronic, Endoscopy, Horse, Mycology, Respiratory,

Abstract :

Diseases of the upper respiratory tract have been considered due to their association with athletic performance and horse health. Among infectious disorders, fungal infections have been a challenge for equine veterinarians due to their resistance to treatment. The aim of this study was to investigate the origin of secretions from the nostrils and its association with upper respiratory tract diseases. 10 horses with secretions from nostrils that did not respond to treatment, after segregation by age, sex and breed, underwent endoscopic rest and mycological sampling. Sedation was performed by administering Detomidine Hydrochloride at a dose of 0.04 mg / kg. After observing the nose, throat and larynx and the space inside the guttural pouch, disorders such as nasal inflammation, epiglottis involvement, epiglottis enlargement, pharyngeal lymphoid hyperplasia, unilateral laryngeal paralysis, arytenoid cartilage deformity, discharge from the guttural pouch and dorsal soft palate dislocation were examined. Two swabs were taken from each horse, and each was sent to a mycology laboratory in a separate tube, one containing physiological serum plus chloramphenicol and the other containing Sabouraud Dextrose agar plus chloramphenicol. Nine head of the studied horses had upper respiratory tract abnormalities. Lymphoid hyperplasia was the most common among upper respiratory tract abnormalities. The result of mycological culture was positive for every 10 heads. In only one head, guttural pouch was the source of the discharge. Among the obtained fungi, Aspergillus fumigatus was the most abundant. The present study showed that most discharges from nostrils that do not respond to drug treatment are due to fungal infections and definitive diagnosis is possible with the help of biopsy and endoscopic examination. In future studies, it is suggested that in addition to the use of field endoscopy, and a wider statistical population should be examined.

References:

1. Hodgson DR, McKeever KH, McGowan CM. The athletic horse: principles and practice of equine sports medicine. 2nd ed. 2014. 398 p. doi:10.1016/C2009-0-46058-6.
2. Franklin SH, Allen KJ. Assessment of dynamic upper respiratory tract function in the equine athlete. Equine Vet Educ. 2017;29 (2):92-103. doi:10.1111/eve.12432.
3. Kelly PG, Reardon RJM, Johnston MS, Pollock PJ. Comparison of dynamic and resting endoscopy of the upper portion of the respiratory tract in 57 Thoroughbred yearlings. Equine Vet J. 2013; 45 (6):700-4. doi:10.1111/evj.12061.
4. Seyedmousavi S, Bosco S, De Hoog S, Ebel F, Elad D, Gomes RR, et al. Fungal infections in animals: a patchwork of different situations. Med Mycol. 2018; 56 (suppl_1):S165-87. doi:10.1093/mmy/myx104.
5. Katiraei F, Khordadmehr M. 2019. Pathology of Fungal Diseases in Domestic Animals, Pathology of Fungal Diseases. Tabriz University Press. p. 70-75.
6. Khosravi A. Medical Mycology, Practical Methods, Culturing and Isolating Fungi. Jahad Daneshgahi Tehran Unit Press; 2003. p. 67-86.
7. Khosravi A. Veterinary Mycology, Characteristics of Fungi. Jahad Daneshgahi Tehran Unit Press; 2005. p. 144-145.
8. Klingspor L, Jalal S. Molecular detection and identification of Candida and Aspergillus spp. from clinical samples using real-time PCR. Clin Microbiol Infect. 2006; 12(8):745-53. doi:10.1111/j.1469-0691.2006.01498.x.
9. Stirling D. DNA extraction from fungi, yeast, and bacteria. Methods Mol Biol. 2003; 226: 53-4. Available from: https://link.springer.com/protocol/10.1385/1-59259-384-4:53
10. Fredricks DN, Smith C, Meier A. Comparison of six DNA extraction methods for recovery of fungal DNA as assessed by quantitative PCR. J Clin Microbiol. 2005; 43 (10):5122-8. doi:10.1128/jcm.43.10.5122-5128.2005.
11. Glass NL, Donaldson GC. Development of primer sets designed for use with the PCR to amplify conserved genes from filamentous ascomycetes. Appl Environ Microbiol. 1995; 61(4):1323-30. doi:10.1128/AEM.61.4.1323-1330.1995.
12. White TJ, Bruns TD, Lee SB, Taylor JW. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. 2024. Available from: https://www.researchgate.net/publication/223397588
13. Dauvillier J, ter Woort F, van Erck-Westergren E. Fungi in respiratory samples of horses with inflammatory airway disease. J Vet Intern Med. 2019; 33 (2):968-75. doi:10.1111/jvim.15397.
14. Dobiáš R, Jahn P, Tóthová K, Dobešová O, Višňovská D, Patil R, et al. Diagnosis of aspergillosis in horses. J Fungi. 2023; 9 (2):161. doi:10.3390/jof9020161.
15. Kelly PG, Reardon RJM, Johnston MS, Pollock PJ. Comparison of dynamic and resting endoscopy of the upper portion of the respiratory tract in 57 Thoroughbred yearlings. Equine Vet J. 2013; 45 (6):700-4. doi:10.1111/evj.12061.
16. Lane JG, Bladon B, Little DRM, Naylor JRJ, Franklin SH. Dynamic obstructions of the equine upper respiratory tract. Part 2: comparison of endoscopic findings at rest and during high-speed treadmill exercise of 600 Thoroughbred racehorses. Equine Vet J. 2006; 38 (5):401-8. doi:10.2746/042516406778400619.
17. Shawaf TM. Endoscopic diagnosis and management of an unusual nasal foreign body in a mare. Int J Vet Sci Med. 2017; 5 (1):81-3. doi:10.1016/j.ijvsm.2017.05.002.
18. Tan RHH, Dowling BA, Dart AJ. High-speed treadmill videoendoscopic examination of the upper respiratory tract in the horse: the results of 291 clinical cases. Vet J. 2005; 170 (2):243-8. doi:10.1016/j.tvjl.2004.06.011.
19. Joo K, Szenci O, Bohak Z, Povazsai A, Kutasi O. Evaluation of overground endoscopy findings in sport and pleasure horses. J Equine Vet Sci. 2015; 35 (9):756-62. doi:10.1016/j.jevs.2015.07.016.
20. Handbook of equine respiratory endoscopy. [Cited 2024]. Available from: https://vetbooks.ir/handbook-of-equine-respiratory-endoscopy.
21. Barakzai SZ, Cheetham J. Endoscopic examination of exercising horses: effects on diagnosis and treatment of upper respiratory tract disorders. Equine Vet J. 2012; 44 (5):501-3. doi:10.1111/j.2042-3306.2012.00625.x.
22. Garrett KS, Woodie JB, Embertson RM. Association of treadmill upper airway endoscopic evaluation with results of ultrasonography and resting upper airway endoscopic evaluation. Equine Vet J. 2011; 43 (3):365-71. doi:10.1111/j.2042-3306.2010.00216.x.
23. Ludwig A, Gatineau S, Reynaud MC, Cadoré JL, Bourdoiseau G. Fungal isolation and identification in 21 cases of guttural pouch mycosis in horses (1998-2002). Vet J. 2005; 169 (3):457-61. doi:10.1016/j.tvjl.2004.06.005.
24. Dixon PM, Froydenlund T, Luiti T, Kane-Smyth J, Horbal A, Reardon RJM. Empyema of the nasal conchal bulla as a cause of chronic unilateral nasal discharge in the horse: 10 cases (2013-2014). Equine Vet J. 2015; 47 (4):445-9. doi:10.1111/evj.12316.
25. Wood JLN, Newton JR, Chanter N, Mumford JA. Inflammatory airway disease, nasal discharge and respiratory infections in young British racehorses. Equine Vet J. 2005; 37 (3):236-42. doi:10.2746/0425164054530599.
26. Bosshard S, Gerber V. Evaluation of coughing and nasal discharge as early indicators for an increased risk to develop equine recurrent airway obstruction (RAO). J Vet Intern Med. 2014; 28 (2):618-23. doi:10.1111/jvim.12294.
27. Vlaminck L, Pollaris E, Vanderperren K, Tremaine WH, Raes E. Diagnosis and surgical treatment of idiopathic primary sino-nasal obstruction in miniature horse breeds: long-term follow-up of seven cases. Front Vet Sci. 2021; 8:680150. doi:10.3389/fvets.2021.680150.
28. Bastani B, Raoofi A, Madadgar O, Akbarein H. Investigation of equine arteritis virus infection using ELISA in horses with a history or clinical signs of the disease from four provinces of Iran. J Vet Res. 2020; 75 (2):200-7. doi:10.22059/jvr.2020.294676.2931.
29. Moghaddam S, Lotfollahzadeh S, Salehi TZ, Hassanpour A, Manesh HT, Akbarein H. Frequency and potential components affecting infections caused by beta-hemolytic streptococci in the respiratory tract of horses with clinical symptoms in breeding centers in northwest Iran. J Vet Res. 2023; 78 (2):97-107. doi:10.22059/jvr.2023.352017.3220.
30. Tazikeh A, Raoofi A, Madadgar O, Akbarein H, Mashhadi AG. Investigation of equine herpesvirus type 4 infection using Real-Time PCR TaqMan in four selected provinces of Iran. J Vet Res. 2018; 73 (4):483-90. doi:10.22059/jvr.2018.252271.2816.