Efficacy and safety of topical administration of selamectin for treatment of ear mite infestation in rabbits.
OBJECTIVE
To evaluate the efficacy and safety of topical administration of selamectin in rabbits naturally infested with Psoroptes cuniculi.


METHODS
Randomized controlled trial.


METHODS
48 mixed-breed domestic rabbits with active P. cuniculi mite populations and clinical ear lesions.


METHODS
Rabbits were randomly allocated to 1 of 6 treatment groups. On day 0, rabbits in groups 1 and 2 were given vehicle, rabbits in groups 3 and 4 were given selamectin at a dose of 6 mg/kg (2.7 mg/lb), and rabbits in groups 5 and 6 were given selamectin at a dose of 18 mg/kg (8.2 mg/lb). On day 28, rabbits in groups 2, 4, and 6 were given a second dose of vehicle or selamectin. Otoscopic examinations were performed and ear lesion size was measured weekly for 8 weeks. Quantitative viable mite counts were performed on day 56.


RESULTS
On days 7 through 56, lesion sizes for all selamectin-treated groups were significantly lower than sizes for control groups; there were no significant differences in lesion sizes among selamectin-treated groups. All rabbits in the 2 control groups had viable adult P. cuniculi mites for the duration of the study, as determined by otoscopic examination, whereas all rabbits in the 4 selamectin-treated groups were free from P. cuniculi mites on days 7 through 56. No adverse reactions associated with selamectin treatment were observed.


CONCLUSIONS
Results suggest that topical application of selamectin at a dose of 6 or 18 mg/kg can completely eliminate mites from rabbits naturally infested with P. cuniculi.
McTier
Tom L
TL
Pfizer Animal Health, Veterinary Medicine Research and Development, Groton, CT 30604, USA.
Hair
J Alexander
JA
Walstrom
Douglas J
DJ
Thompson
Leland
L
D000287:Administration, Topical; D000818:Animals; D000977:Antiparasitic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004431:Ear, External / Q000469:parasitology* / Q000473:pathology; D005260:Female; D007559:Ivermectin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D008297:Male; D008924:Mite Infestations / Q000188:drug therapy / Q000662:veterinary*; D011817:Rabbits / Q000469:parasitology*; D011897:Random Allocation; D016896:Treatment Outcome
D000977:Antiparasitic Agents; D007559:Ivermectin; C414354:selamectin