First Feline Case of Otodectosis in the Republic of Korea and Successful Treatment with Imidacloprid/Moxidectin Topical Solution

Abstract

In April 2010, pruritic symptoms were recognized in 3 privately-owned Siamese cats raised in Gwangju, Korea. Examination of ear canals revealed dark brown, ceruminous otic exudates that contain numerous live mites at various developmental stages. Based on morphological characteristics of adult mites in which caruncles were present on legs 1 and 2 in adult females and on legs 1, 2, 3, and 4 in adult males while the tarsus of leg 3 in both sexes was equipped with 2 long setae, the mite was identified as Otodectes cynotis. Ten ear mite-free domestic shorthaired cats were experimentally infected with O. cynotis to evaluate the efficacy of 10% imidacloprid/1% moxidectin spot-on. Live mites were recovered from 1 of 10 treated cats on day 9 post-treatment (PT) while no live mites were observed from the ear canals of treated cats on days 16 and 30 PT. The efficacy of 10% imidacloprid/1% moxidectin spot-on on O. cynotis in cats was, therefore, 90% on day 9 and 100% on days 16 and 30 PT. This is the first report of otodectosis in 3 cats naturally infested with O. cynotis in Gwang-ju, Korea. Both natural and experimental infestations were successfully treated with 10% imidacloprid/1% moxidectin spot-on.

Evidence‐based veterinary dermatology: a review of published studies of treatments forOtodectes cynotis(ear mite) infestation in cats

“…Five clinical trials investigated the efficacy of topical 10% imidacloprid +1% moxidectin (Advantage Multi ® or Advocate; Bayer Animal Health) at the base of the neck including one blinded RCT and four open studies (Table ) . The overall efficacy for treatment of one dose of Advantage Multi ® was 92.8% (77 of 83) and the overall efficacy for two doses 30 days apart was 98.4% (62 of 63) . The result from one study was not included for calculation of the overall efficacy due to a different method used for assessment of clinical outcome .…”

“…The efficacy of two doses of imidacloprid +1% moxidectin and selamectin 30 days apart were compared in one study, where imidacloprid + moxidectin provided an efficacy of 98.1% (52 of 53) whereas selamectin provided an efficacy of 95.8% (23 of 24) . Complete absence of mites for all cats was observed from day 16–22 after treatment in three studies . Adverse effects of imidacloprid + moxidectin were observed in two cats: one appeared dazed and one showed excessive salivation …”

“…Quality of inclusion of study subjects was well‐characterized in most of the studies, which largely mentioned the observation of live mites in the ears of infested animals. Most studies enrolled cats only if they were presented with both clinical signs and ear mite infestation, whereas some studies enrolled cats that were not necessarily presented for ear problems . Difference in treatment effect also may have existed between patient groups because both adult cats and kittens under 6 months of age were allocated randomly to groups in some studies reviewed; this could affect the external validity.…”

“…15,[40][41][42][43] The overall efficacy for treatment of one dose of Advantage Multi â was 92.8% (77 of 83) and the overall efficacy for two doses 30 days apart was 98.4% (62 of 63). [40][41][42][43] The result from one study was not included for calculation of the overall efficacy due to a different method used for assessment of clinical outcome. 15 The efficacy of two doses of imidacloprid +1% moxidectin and selamectin 30 days apart were compared in one study, where imidacloprid + moxidectin provided an efficacy of 98.1% (52 of 53) whereas selamectin provided an efficacy of 95.8% (23 of 24).…”

“…42 Complete absence of mites for all cats was observed from day 16-22 after treatment in three studies. 40,41,43 Adverse effects of imidacloprid + moxidectin were observed in two cats: one appeared dazed and one showed excessive salivation. 42 Ivermectin Seven studies reported on treatment with ivermectin, including several off-label drugs, they are summarized in Table 4.…”