dog lump on belly

Question
QUESTION: My dog Koda has recently had a large red sore appear on his belly near his male parts. He has had surgery previously for removal of something like this. The only difference this time is that it is forming a hole in it. What could possibly be causing this hole? It appears to have a liquid substance in it.

ANSWER: What was the surgery for and what is causing this if he has had it before? Is it a cyst or a grub inside?
There is nothing I can do here, you need to take him in and have it looked at by the vet. If there is a grub larvae in there it needs to be removed.

If it is a cyst or a tumor it needs to be removed as well.

---------- FOLLOW-UP ----------

QUESTION: The surgery was to remove a tumor. They didn't do a biopsy on out when they removed it. The hole, to me,  is brown on the inside. Kind of reminds me of what ground beef looks like when it browns on the stove.
It is spotting a watery blood. I took him to the vet. They said he would have to go to another place for surgery because of how internal it is. We haven't decided what to do yet. They have him Cefa for antibiotic. Just hard to deal with. Thank you so very much though! Im 21 and have had him since I was either 10 or 11.

Answer
So this could be a tumor that is rotting as well. Well I am glad you took him in so quickly and thank you for letting me know. I understand your bond with your boy, so good for you for doing the best for him.

I am sure he will be fine once this one is removed as well.