Katz, I don't have personal experience, but there was a Pointer in my neighborhood, had a problem regrowing hair after an operation or medical testing. She had a patch of fur shaved off (approx. 6"x6") and it didn't grow back at all for months. However, in early spring, at just about the time when dogs will shed their old coats and grow new ones, her hair grew in just fine. So maybe Nina's hair will grow in properly in the fall when it is time for a new coat to come in.