Microbiological investigation and determination of susceptibility to antimicrobial agents in feline otitis externa

Authors

DOI:

https://doi.org/10.61308/EHPU1598

Keywords:

antimicrobial susceptibility, microbial agents, otitis externa, cats

Abstract

This study aimed to investigate the bacterial and yeast populations in cats with otitis externa, and to assess their susceptibility to antimicrobial agents. Fifty-six cats showing clinical signs of otitis externa were included in the study. The cats were of different ages, genders, and breeds. Sterile cotton swabs were used to collect samples from the external ear canal, and conventional microbiological techniques as well as biochemical testing were used to isolate and identify the microorganisms. Antimicrobial susceptibility testing was conducted using Kirby-Bauer's disc diffusion method. Of 56 swab samples analyzed, 8 (14.28%) showed no microbial growth, while Malassezia pachydermatis was found in 26.79% of the samples, followed by Staphylococcus aureus (25%), Pseudomonas aeruginosa (12.5%), Proteus mirabilis (10.71%), and Staphylococcus pseudintermedius (5.36%). The examined bacterial isolates exhibited the highest sensitivity to ciprofloxacin, gentamicin, amikacin, and doxycycline.

References

Baxter, M. & Lawle, D. C. (1972). The incidence and microbiology of otitis externa of dogs and cats in New Zealand. New Zealand Veterinary Journal, 20(3), 29 - 32. DOI: 10.1080/00480169.1972.33996. DOI: https://doi.org/10.1080/00480169.1972.33996

Bollez, A., de Rooste, H., Furcas, A. & Vandenabeele, S. (2018). Prevalence of external ear disorders in Belgian stray cats. Journal of Feline Medicine and Surgery, 20(2), 149 - 154. DOI: 10.1177/1098612X17700808. DOI: https://doi.org/10.1177/1098612X17700808

Cafarchia, C., Gallo, S., Capelli, G. & Otranto, D. (2005). Occurrence and population size of Malassezia spp. in the external ear canal of dogs and cats both healthy and with otitis. Mycopathologia, 160(2), 143 - 149. DOI: 10.1007/s11046-005-0151-x. DOI: https://doi.org/10.1007/s11046-005-0151-x

CLSI. (2020). Performance Standards for Antimicrobial Disk and Dilution Susceptibility Test for Bacteria Isolated from Animals; Approved Standard Document 5th ed. CLSI supplement VET01S.

CLSI. (2019). Performance Standards for Antimicrobial Susceptibility Testing. 29th ed. CLSI supplement M100. Wayne, PA ABD.

Degi, J., Cristina, R.T., Fodor, I.F., Herman, V. & Catana, N. (2012). Prevalence of antimicrobial susceptibility of staphylococci isolated from otitis externa of cats. Romanian Journal of Veterinary Sciences, XLV(3), 43 - 47. Timişoara.

Dizzoti, C. E. & Coutinho, S. D. (2007). Isolation of Malassezia pachydermatis and M. sympodialis from the external ear canal of cats with and without otitis externa. Acta Veterinaria Hungarica, 55(4), 471 - 477. DOI: 10.1556/AVet.55.2007.4.6. DOI: https://doi.org/10.1556/avet.55.2007.4.6

Hariharan, H., Coles, M., Poole, D., Lund, L. & Robert, P. (2006). Update on antimicrobial susceptibilities of bacterial isolates from canine and feline otitis externa. Canadian Veterinary Journal, 47(3), 253 - 255. PMCID: PMC1371054.

Harvey, R. G., Harari, J. & Delauche, A. J. (2001). Ear diseases of the dog and cat. In: Medical management of ear disease. Nohrtcott J. (ed.). Manson Publishing, 161 - 212.

Hiblu, M. A., Ellrais, O. M., Karim, E. S., Elmishri, R. A., Duro, E. M., Altaeb, A. A. & Bennour, E. M. (2020). Otodectic and bacterial etiology of feline otitis externa in Tripoli, Libya. Open Veterinary Journal, 10(4), 377 - 383. DOI: http://dx.doi.org/10.4314/ovj.v10i4.4. DOI: https://doi.org/10.4314/ovj.v10i4.4

Hill, P. B., Lo, A., Eden, C. A. N., Huntley, S., Morey, V., Ramsey, S., Richardson, C., Smith, D. J., Sutton, C., Taylor, M. D., Thorpe, E., Tidmarsh, R. & Williams, V. (2006). Survey of the prevalence, diagnosis and treatment of dermatological conditions in small animals in general practice. The Veterinary Record, 158(16), 533 - 539. DOI: 10.1136/vr.158.16.533. DOI: https://doi.org/10.1136/vr.158.16.533

Guardabassi, L., Schwarz, S. & Lloyd, D. H. (2004). Pet animals as reservoirs of antimicrobial-resistant bacteria. The Journal of Antimicrobial Chemotherapy, 54(2), 321 - 332. DOI: 10.1093/jac/dkh332. DOI: https://doi.org/10.1093/jac/dkh332

Jacobson, L. S. (2002). Diagnosis and medical treatment of otitis externa in the dog and cat. Journal of the South African Veterinary Association, 73(4), 162 - 170. DOI: 10.4102/jsava. v73i4.581. DOI: https://doi.org/10.4102/jsava.v73i4.581

Kennis, A. R. (2013). Feline otitis: diagnosis and treatment. The Veterinary clinics of North America. Small animal practice, 43(1), 51 - 56. DOI: 10.1016/j.cvsm.2012.09.009. DOI: https://doi.org/10.1016/j.cvsm.2012.09.009

Kittl, S., Brodard, I., Rychener, L., Jores, J., Roosje, P. & Gobeli Brawand, S. (2018). Otitis in a cat associated with Corynebacterium provencense. BMC Veterinary Research, 14(1), 1 - 6. DOI: 10.1186/s12917-018-1526-9. DOI: https://doi.org/10.1186/s12917-018-1526-9

Li, Y., Fernandez, R., Duran, I., Molina-Lopez, R. A. & Darwich, L. (2021). Antimicrobial resistance in bacteria isolated from cats and dogs from the Iberian Peninsula. Frontiers in Microbiology, 11, 621597. DOI: 10.3389/fmicb.2020.621597. DOI: https://doi.org/10.3389/fmicb.2020.621597

Lloyd, D. H. (2007). Reservoirs of antimicrobial resistance in pet animals. Clinical Infectious Disease, 45(Suppl. 2), S148 - S152. DOI: 10.1086/519254. DOI: https://doi.org/10.1086/519254

Mascarenhas, M. B., Botelho, C. B., Manier, B. S. M. L., Costa, T. S. & Fernandes, J. I. (2019). An unusual case of feline otitis externa due to sporotrichosis. Journal of Feline Medicine and Surgery Open Reports, 5(1), 2055116919840810. DOI: 10.1177/2055116919840810. DOI: https://doi.org/10.1177/2055116919840810

Nardoni, S., Mancianti, F., Rum, A. & Corazza, M. (2005). Isolation of Malassezia species from healthy cats and cats with otitis. Journal of Feline Medicine and Surgery, 7(3), 141 - 145. DOI: 10.1016/j.jfms.2004.07.005. DOI: https://doi.org/10.1016/j.jfms.2004.07.005

Nardoni, S., Ebani, V.V., Fratini, F., Mannella, R., Pinferi, R., Mancianti, F., Finotello, R. & Perrucci, S. (2014). Malassezia, mites and bacteria in the external ear canal of dogs and cats with otitis externa. Slovenian Veterinary Research, 51(3), 113 - 118.

Perego, R., Proverbio, D., Bagnagatti De Giorgi, G., Della Pepa, A. & Spada, E. (2014). Prevalence of otitis externa in stray cats in northern Italy. Journal of Feline Medicine and Surgery, 16(6), 483 - 490. DOI: 10.1177/1098612X13512119. DOI: https://doi.org/10.1177/1098612X13512119

Qekwana, D. N., Sebola, D., Oguttu, J. W. & Odoi, A. (2017). Antimicrobial resistance patterns of Staphylococcus species isolated from cats presented at a veterinary academic hospital in South Africa. BMC Veterinary Research, 13(1), 286. DOI: 10.1186/s12917-017-1204-3. DOI: https://doi.org/10.1186/s12917-017-1204-3

Rosser, E. J. (2004). Causes of otitis externa. The Veterinary clinics of North America. Small animal practice, 34(2), 459 - 468. DOI: 10.1016/j.cvsm.2003.10.006. DOI: https://doi.org/10.1016/j.cvsm.2003.10.006

Shokri, H., Khosravi, A., Rad, M. & Jamshidi, S. (2010). Occurrence of Malassezia species in persian and domestic short hair cats with and without otitis externa. The Journal of Veterinary Medical Science, 72(3), 293 - 296. DOI: 10.1292/jvms.09-0421. DOI: https://doi.org/10.1292/jvms.09-0421

Topala, R., Burtan, I., Fantanaru, M., Ciobanu, S. & Burtan, L.C. (2007). Epidemiological studies of otitis externa at carnivores. Lucrari Stiintifice Medicina Veterinara, 40, 647 - 651.

Tyler, S., Swales, N., Foster, A.P., Knowles, T.G. & Barnard, N. (2020). Otoscopy and aural cytological findings in a population of rescue cats and cases in a referral small animal hospital in England and Wales. Journal of Feline Medicine Surgery, 22(2), 161 - 167. DOI: 10.1177/1098612X19834969. DOI: https://doi.org/10.1177/1098612X19834969

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Published

29.10.2026

How to Cite

Robaj, A., Sylejmani, D., & Mazreku, N. (2026). Microbiological investigation and determination of susceptibility to antimicrobial agents in feline otitis externa. Bulgarian Journal of Agricultural Science, 32(5), 1198-1202. https://doi.org/10.61308/EHPU1598