Why are my dogs suddenly fighting?

I have 2 dogs..ome is a rex terrior and one is a pitbull..they once got along and would even share a doggy bed. then a couple of weeks ago they fought and one dog was hurt badly and we took her to the vet. now shes better but what should I do about this?

Firstly..How cute!! Anyway,there are many issues involved and lots of questions. Are they neutered?? Are they both female or one of each? Dogs will tend to fight primarily for dominance as in a pack,there has to be a leader. I would advise that my questions be considered and further advice be sought from a vet to establish this problem as it will only get worse and it is probably a very simple thing to correct.Good Luck and hope I have helped..

your not allowed pitt bull terriers