This article given in the above post points out that the Bayer is "unaware of any published data showing a similar failure of moxidectin product applied to the skin". The CAPC confirmed this. "Topical moxidectin is thought to result in higher plasma levels than injectable moxidectin"-stated by CAPC parasitologist Little. Research supports a non-failure rate to-date on topical moxidectin aka Advantage Multi. Pretty impressive thus far