what does Koa have near his private area it like a growth?
Agree it should be checked out by a Vet. Could even be a urine burn, in which case, her urine should be checked. Could be vaginal infection, yeast, contact dermatitis problem, etc. Perhaps cultures need to be done
This could be a condition known as Pyoderma, where ulceration and sores occur on skin folds. To know for sure, you need to take her to be examined by the vet.
They may do a culture to be sure if bacteria are present, and then it would probably be treated with antibiotics.
Check this out with your vet.