Field Comparison of the Impact of Different Treatment Durations in the Treatment of Acute Otitis Externa

Abstract

Background: Acute otitis externa is a common multi-factorial disorder in the dog. Several topical preparations are available on the veterinary market, which are licensed for an either specified duration of treatment or for a discretionary period that is determined by the clinician. Objectives: To compare the efficacy of two topical products, both licensed for the treatment of otitis externa in the dog, but with different treatment durations. Animal Population: One hundred and sixty dogs were enrolled in this multicentre field study from which 157 dogs were analysed in the Per Protocol sam-ple (73 Aurizon ® treated animals and 84 Easotic ® treated animals). Method: Dogs were randomly assigned to Aurizon ® or Easotic ® treatment groups. Aurizon ® (Vétoquinol SA: marbofloxacin, clotrimazole, dexamethasone) was administered daily in the affected ear(s) for 7 or 14 days, and was compared with a daily administration of Easotic ® (Virbac SAS: gentamicin, miconazole, hydrocortisone aceponate) for 5 days. General and localised clinical signs were scored on days 0 (D0), 3 (D3), 7 (D7), 14 (D14) and 21 (D21). Results: Clinical cure rates at the end of treatment were 56.3% and 48.8% (p = 0.35) in the Aurizon ® and Easotic ® groups respectively and 81.2% versus 74.7% one week after completing the course of treatment (p = 0.34). Twenty-one days after initially presenting for the study, cure rates were 84.3% in the Aurizon ® group and 73.8% in the Easotic ® (p = 0.12). A relationship between severity of clinical signs and treatment duration was observed. Conclusion and Clinical Significance: At the end of the trial period, cure rates showed a ten-dency to be higher in the Aurizon ® treated animals. The flexible dosage and the veterinary monitoring permitted treat-ment duration to be adjusted based upon the severity of otitis externa thus increasing the likelihood of clinical cure.