My vet said it was fine when I bought it. I have many dogs in our practice on Frontline TopSpot and have never heard of the reaction that you reported - in fact, I have yet to see an adverse reaction to this product. My suggestion would be to reapply it in one month and look to see if you get the same reaction. If you can reproduce the results then it is unlikely to be a coincidence. These were hand picked from her.
Ticks seem to love greyhounds, probably because of their relatively thin skin.
The easiest way to prevent them from attaching is to use Frontline, either spray or spot on, monthly. Your vet should be able to supply you with this. Other than removing the ticks, there is nothing else you should have to do for the skin. It will take care of itself once the ticks are gone.