After a trip to the vets last week and being told my dog had a tumour, and booked in for a £200 operation I have discovered it was actually a cyst, which has popped tonight. I've cleaned it and am confident that the filling and sac have been removed, but there's a bit of a "gap" in the skin now. Should I leave it to air, pop some sudocrem and a bandage on it? I will take him to a (different 
) vet too in case he needs antibiotics or something.