Evaluation of fungal flora in normal and diseased canine ears

Abstract

This study was undertaken to characterize otic fungal flora encountered in normal dogs, atopic dogs with no clinical or cytological evidence of otitis and dogs with otitis externa. Forty-two normal dogs, 23 atopic dogs and 32 dogs with otitis were included in the study. Samples for otic fungal culture and cytology were obtained from all animals, for a total of 194 ears. Sixty-seven ear samples (34%) were culture positive for saprophytic fungal organisms, as follows: 43 (64%) Penicillium species, 13 (19%) Aspergillus species and the remaining 17% comprised of various other saprophytic fungal organisms. Cytological evidence of saprophytic fungal colonization or infection was not found in any animal. There was no relationship between positive saprophytic fungal culture and any study group. Thirty-three ear samples (17%) were positive for Malassezia pachydermatis. Cytological findings of Malassezia were significantly associated with positive culture for Malassezia (P = 0.006 left ear; P = 0.019 right ear). Furthermore, increased numbers of Malassezia led to a higher chance of positive culture (P = 0.003 left ear; P = 0.008 right ear; McNemar's test). Malassezia pachydermatis was more likely to be cultured from ears with increased cerumen. Ear type (erect or pendulous) was not significantly associated with positive culture for Malassezia or saprophytic fungal organisms. There was no relationship between positive Malassezia culture and any study group; however, Malassezia was more likely to be cultured from individual dogs in the atopic or otitis groups that also had other dermatological signs consistent with allergic dermatitis and/or pyoderma (P = 0.031 left ear; P = 0.005 right ear).

MalasseziaversusCandidain Healthy Dogs

“…In general, Malassezia yeasts are associated with the skin and mucous membranes in healthy and diseased dogs [9,10,22,30,31]. Even 62.9 % of the dogs are positive for Malassezia yeasts.…”

Antimycotic Activity of Some Aromatic Plants Essential Oils Against Canine Isolates of Malassezia pachydermatis: An in vitro Assay

“…Malassezia pachydermatis is a normal commensal and occasional pathogen of the skin and mucosae in Carnivora, and represents the most frequently isolated yeast in canine external otitis [5]. Most cases of Malassezia otitis in the dog are associated with concurrent skin disorders or systemic diseases.…”

Comparison of lipid profiles of Malassezia pachydermatis strains isolated from dogs with otitis externa and without clinical symptoms of disease

“…The most common disease caused by M. pachydermatis diagnosed in dogs is otitis externa. 21 However, the aetiology, predisposing factors and pathogenic role of microorganisms are not fully explained. Accurate and early diagnosis, which is determining the cause of the disease, is extremely important.…”