Hello, first of all, I'm sorry for the late reply. It is difficult to answer correctly because there is no picture of the part of your dog. If you send me the photo, I will help you with more detailed consultation later. Make sure that your dog's wound is not infected with a secondary infection. Secondary infections are when the area is swollen, pus come out, and a lot of exudate comes out.
In this case, bacteria, fungi, etc. may have been secondaryly infected with the wound.
In this case, please visit the animal hospital for accurate diagnosis and treatment.

For primary wound lesions, wipe the area with sterile physiological saline, disinfect it with beta-dine disinfectant, and apply an ointment containing antibiotics, repeat twice a day.
If the wound does not recover within 5-7 days, please visit an animal hospital.

There's a bump on Milos undercarriage near his boobs in front of his red rocket I just noticed. Can't have been there long ...what do I do??

I just noticed a bump on his undercarriage