Cytological and Microbiological Evaluation of External Otitis in Dogs--Preliminary Results
A. Alves; L.R. Signorelli; L.F. Paula; K.D. Oliveira; M.A.V. Beltrame; L.M.C. Conti; G.L. Pissinate; V.K. Arruda
Veterinary Medicine Course, University Center of Vila Velha, Vila Velha, Espírito Santo, Brazil
External otitis is observed in 15% of the canine consultations. Factors involved in its development can be primary (atopic, alimentary hypersensitivity, keratinization disturbances and otocariasis), predisposing (obstructive auricular disease) or perpetuate (yeast and bacteria). The most predisposed are dogs with pendular ears. The main clinical signs are otorrhea, otalgia, pruritus, cephalic shaking and stenosis of the hearing conducts. The diagnosis is based on anamnesis and physical exams, however the otoscopy is an important procedure for the detection of polyps, neoplasias, strange bodies, exudation, bleeding and the evaluation of the middle ear. Cerumen cytology must be done in order to research for perpetuate factors and to classify the inflammatory infiltration. Culture and antibiogram are recommended to know the microorganisms involved in order to choose the right treatment. The objective of this work is to report the preliminary results of cytological and microbiological exams of dog ears showing external otitis attended at the Veterinary Hospital "Professor Ricardo Alexandre Hippler" at the University Center of Vila Velha. Up to now, 25 dogs with clinical signs of external otitis were considered in the study, of which 56% have pendular ears, 16% erect ears and 28% intermediary ears. Otoscopy showed that 84% of the hearing conducts were erythematosus, 24% were stenotic, 20% were lichenifelded, 36% had fur in them, 16% had ectoparasites, 96% had excessive exudation (64% dark and 32% purulent). Cytology showed that 56% of all animals examined had fungal otitis (75% of Malassezia pachydermatis, 12,25% of Candida sp and 12,25% of M. pachydermatis with Candida sp), 28% had mixed otitis (85,72% had coccus with M. pachydermatis and 14,28% had M. pachydermatis with Candida sp and coccus) and eight percent had bacteria otitis (66,66% of coccus and bacillus and 33,33% only with coccus). Of the animals with bacteria otitis, 86% had Staphylococcus intermedius, nine percent had Proteus vulgaris and five percent had Escherichia coli. The antibiogram showed that the strains of Staphylococcus intermedius were more sensitive to tobramycin and gentamycin in 72% of the cases and to cephalothin in 64% of all patients. Of all the animals that presented Proteus vulgaris, 50% were resistant only to neomycin, however the cases of Escherichia coli were sensitive only to gentamycin and enrofloxacin. Considering these data, the relevance of a correct diagnostic approach is evident in order to establish the appropriate therapy reducing the cases of bacteria resistance and the other aggravating cases of chronicity and recurrence.