I noticed this black sore looking thing today when I was petting the dog. I don't I know it wasn't there a couple of days ago. My first thought was testicle cancer, but now I think it looks more like a sore. We called the emergency vet and they said it might be from allergies or licking and to not to come in but to make an appointment with our regular vet on Monday. I am still very concerned and wondering if anyone has ever seen anything like this? It seems to feel uncomfortable when I directly touch the area but other than that the dog is acting normal, playing eating. Should I put anything on it? What could have caused it, he likes to hump a stuffed toy we have could it be from friction burn? Also he sometimes rubs his stomach on the carpet.
Any advise would be greatly appreciated!!
Thank you!

I wouldn't put anything on it, you could make the problem worse. my dog occasionally gets bacterial skin infections, the skin on her belly gets black areas and she has sores, also its kind of hard to tell from the picture but it maybe could be a bruise????? I would leave it alone, and make sure the dog dosn't lick or chew at it or irritate it (humping, etc), and see your vet on monday.

Did this just appear? It does almost look like some kind of bruise I would agree, but it looks blackish...blood underneath? After you take your dog to the vet I'd be interested to know what it is.

Hope the doggy gets better soon!!