Inhibition and prevention efficacy against mosquito bloodsucking and Dirofilaria immitis infection by administration of topical insecticide.

Inhibition and prevention of mosquito bloodsucking by a topical insecticide, and the consequent infection of Dirofilaria immitis were evaluated using a product containing 10% w/w imidacloprid plus 50% w/w permethrin (I-P solution). Nine healthy beagle dogs divided in three groups of 3 dogs each were administered I-P solution on day 3 (group 1), day 36 (group 2) and not administered (group 3 as a control) before starting the experimental infection. The results showed that the mosquito bloodsucking rate was significantly lower, 12.1% in group 1 (p<0.05) and 11.1% in group 2 (p<0.05), than the 40.6% in group 3, meaning that the inhibition rates in groups 1 and 2 against group 3 were 70.2% and 72.7%. The infection rate of experimental D. immitis infection was 33% in group 1, 33% in group 2 and 100% in group 3, meaning that the prevention rates in groups 1 and 2 against group 3 were 67% and 67%.