Dog Itching After Flea Medicine. Dogs hate the smell of flea treatment as it can be very strong. Itching from flea tick topical medicine.

A little mild rubbing of the area immediately after applying a topical flea preventative is normal. For adult fleas to reproduce they must bite a dog to obtain a blood meal. If the dog is allergic to fleas, it can cause severe reactions like scratching, flaky skin, hot spots, etc.