Malassezia otit hos hund
utvärdering av lokal behandling med betametason, ekonazol respektive ättiks- och borsyrelösning
Malassezia otitis in dogs is a common cause of visit to a veterinary service. In otitis externa due to Malassezia overgrowth the dog has a higher number of yeast organisms and/or a local inflammatory response to the micro organism. Common clinical signs include pruritus, erythema, swelling and increased exudate production. Clinical symptoms and results from cytology of ear swabs from the ear canal is the mainstay for diagnosis. Any underlying condition has to be identified and corrected to avoid relapse.
The treatment options for infective otitis externa are based upon topical administration of eardrops containing antibiotics, steroids and antifungals. For the time being there is no registered preparation available in Sweden for the treatment of a Malassezia otitis with no bacterial component. All otic preparation for topical use also contains antibiotics.
The aim of this randomly and prospective study was to evaluate and compare three different treatment protocols in the treatment of canine Malassezia otitis externa. The three treatment options chosen were betametasone (Betnovat), ekonazole (Pevaryl) and acetic-boric acid combination (MalAsetic Otic). All these topical treatments are widely used in Swedish small animal veterinary practice, but to date no study has been published comparing the efficacy of these treatment regimens.
30 dogs were included in the study of which 10 were registered as drop outs. The veterinary graded clinical signs at inclusion and at follow up after 14 days by the use of a clinical scoring system for pruritus, erythema, swelling and amount of exudate. Cytological evaluation was performed at inclusion and at follow up. Cytology at follow up was evaluated blinded to the investigator. The results were calculated in 20 dogs of which 7 were treated with Betnovat, 7 with Pevaryl and 6 with MalAetic Otic. There was a significant difference between Pevaryl compared to Betnovat and MalAsetic Otic. Completely healthy dogs (clinical and cytological cure) after treatment were 86 % for Betnovat, 67% for MalAsetic Otic and 14 % for Pevaryl. The clinical signs at inclusion were more severe in the Pevaryl group as compared to the others, especially with respect to swelling, and this could possibly bias the outcome. No side effect could be noticed in any of the treatment groups.
In summary: This pilot-study shows that topical treatment of Malassezia-associated otitis externa in dogs is effective and safe when using betametasone (Betnovat) and acetic-boric acid combination (MalAsetic Otic). The efficacy of ekonazole (Pevaryl) was significant lower. The statistical power will improve by larger treatment groups and the study will continue, aiming to include 38 dogs in each treatment group.