Compared Efficacy of Three Anti-Mite Drugs Used to Treat Otoacariasis Caused by Otodectes cynotis in Domestic Cats in Puerto Montt, Los Lagos Region, Chile

Abstract

<p>Otodectes cynotis is one the mite causing parasitic dermatosis in the ear pinna of pets. It produces an intense itching and even some ear complications in the absence of an adequate treatment. The prevalence in domestic cats may reach to 37% and accounts for 85 % of the external otitis cases. Products for treating this mite problem are assorted, even though some of them do not state in the labels whether they are intended to any specific species. On the other hand, there is scarce data available on the compared efficacy of the different drugs used for treatment. Mostly used drugs include selamectin, fipronil, thiabendazole, ivermectin, among others. This study aims to compare the anti-mite efficacy of three drugs in the treatment of otoacariasis caused by Otodectes cynotis, administering ivermectin 1%, fipronil 10%, and selamectin 6% to domestic cats in Puerto Montt. One hundred and seventeen domestic cats were examined and 60 were positive to otoacariasis caused by Otodectes cynotis. These 60 patients were divided into four groups with 15 subjects each: group A, ivermectin 1%, ear drops; group B, fipronil 10%, ear drops; group C, selamectin 6%, topical (spot-on); and group D or control group that received a glycerin placebo as ear drops. Checkups were carried out on days 7, 14, 21 and 28 after applying the drugs. The statistical analysis showed significant mild differences between A, B and C groups and the D group. These results suggest that the treatments with ivermectin, fipronil and selamectin in the concentrations, dosages and administration routes indicated above to solve the otoacariasis caused by Otodectes cynotis are equally efficacious, but show some differences in the specific value of each treatment</p>