Catch her and clean the wounds out. They look very dirty so that is not a good thing. By clean, do it the same way you would if you got a big cut your arm. Get the dirt out and get a clear view of the wound and keep her contained in a warm place. If the wound is deep or there is skin tears that are large, a vet may be a good idea so she can get stiches. As for antibiotic to use, someone else will have to advise the best for that. Neosporin would work in the mean time.