While away for holidays, our next door neighbor pet sat our 4 yr old female yellow lab. She owns a female boxer who our dog Gingerbear often plays with. They had a fight over food we were told and Ginger sustained a deep wound in her chest; not sure if inflicted by boxer's teeth or claws. Neighbor is a surgical nurse and cleansed wound with hydrogen peroxide. We've since done so and also applied neosporin ointment; however, wound still very raw in appearance and still secreting pink tinged fluid. My husband feels it will heal on its own. I disagree and think it requires stitches, but he thinks the wound is too old for this treatment. No signs of infection at present.
I recommend a visit to a vet so a doctor can determine if your pet needs surgery. From what you describe it sounds like surgery is the answer. good luck, vetcare