Objective—To evaluate the safety of dermal application
of 10.0% imidacloprid-0.08% ivermectin in ivermectin-
sensitive Collies at dose rates of 3 to 5 times
the proposed maximum therapeutic dose.
Animals—15 Collies (5 males and 10 females) that
were confirmed as ivermectin-sensitive dogs.
Procedure—Dogs were assigned to 3 treatment
groups (control, 3×, or 5× group) in a randomized
block design on the basis of the maximal ivermectinsensitivity
score obtained during preliminary screening.
Dogs in groups 3× and 5× were treated at 3 and
5 times the maximum label dose, respectively.
Control dogs received an application of an equal volume
of a nonmedicated solution. Observation and
scoring on all days were conducted to specifically
include neurologic signs typical of ivermectin toxicosis,
including lethargy, ataxia, abnormal mydriasis, and
Results—None of the dogs had clinical abnormalities
during the study period.
Conclusions and Clinical Relevance—Analysis of
results of this study indicates that dermal application
of 10.0% imidacloprid-0.08% ivermectin is safe for
use in ivermectin-sensitive Collies at dose rates of 3
or 5 times the proposed maximum therapeutic dose.
( Am J Vet Res 2004;65:277–278)