I have a terrier mix who has bumps, and almost feels like scabs on her back. It seems that this has happened several months ago when I took her to a park and she was bit by red ants. I have taken her to the vet, and they tell me it is just sensitive skin. I find this hard to believe since it seems that it is spreading further and further up her back. I wipe her down with non-scented, chemical free baby wipes after each walk. I bathe her once a week with oatmeal shampoo. I have no other pets and she does not interact with any other animals. My house is very clean so I don't suspect ticks (nor have I seen any on her). It doesn't seem to bother her too much, but when I rub my hand on her back it seems like she is in minor discomfort. Any suggestions would greatly help. Thank you.