Hi there and welcome to Just answer!! I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
This lesion may be a hematoma from playing too hard and bruising this area. the best thing to do is to apply hot compresses to this area every 4 hrs. This will help draw any infection to the outside. Once it opens, flush it with peroxide and apply Neosporin to this area every 8 hrs. If Jezzebelle is still eating and active, she will not need antibiotics or the other medications. This will resolve with the treatment that I have described.
Good Luck! Sincerely, XXXXX XXXXX
what do i do if it gets worse. i dont have the money for a vet right now is there anything i can do and thank you so much i will keep up with the hot compresses