Do you also put a mask on the dog? You don't want the dog breathing it in or
getting it into it's eyes either I imagine. A tea towel tied around the
dog's neck and hung over it's head or an Elizabethan collar might do the
trick during application.
Ian

If your dog is being bothered by mites, fleas or other insect critters, you
can dust his/her coat with diatomaceous earth. Make sure it's food grade,
and wear a mask when you dust the animal's coat. If the D.E. is eaten, it
kills parasites.

Nenah