What you have is probably Herpes. Although there is no cure, there are treatments to ease the pain.
ulcers
Canker sores tend to appear in response to stress.
A few causes of sores on dogs backs that bleed are anemia, blood pressure, or dog lice. Dog lice irritate the skin causing oozing sores and crusty ear tips.
Cold sores are a form of herpes. If he has a cold sore and his lips touch your vagina, then you can absolutely get genital herpes.
Yes. Sometimes they do.
It is herpes. Sometimes people refer to them as 'cold sores' but it is the herpes simples virus.
If the sores are located on the belly, then it is likely that you puppy was just neutered. No need to panic, if the sores begin to bleed make an appointment with your vet to have them restitched. If the sores are located elsewhere and you notice your puppy scratching or gnawing, he/she may have allergies. A vet can diagnose the specific allergy and suggest treatment.
Since sex mostly involves friction one can assume that the sores might be caused by chafing.
Canker sores appear as a whitish, round area with a red border. The sores are painful and sensitive to touch.
Blood Letting was popular then. where they would cut the sores and let them bleed
Soap irritation, yeast infection, or possibly, inherited herpes
That is an STD