This afternoon I noticed a good half dozen flies on Frostie the cow's teat. Knew they were bothering her as she kept trying to swipe at it with her hind leg. As I'm new with cattle, I don't quite know how to treat this as she's still feeding her 3 month old heifer calf. Can I spray it with something or will this put the little un off feeding? She's had Spot-on at the beginning of the month.