It's blood pooled up in his scrotum from the surgery. Basically extreme bruising, this could also be initiated more so from too much exercise after surgery, which your vet should have told you no exercise for at least 5 days after surgery. If it's looking really bad and you're concerned, call your vet. My dog was just neutered and the entire bottom of his scrotum is jet black.
Yes it is possible. It would be swollen and be have some bruising.
A male dog has been Neutered.
They're removed and destroyed as biological waste
You need to take your dog in to be checked out by a Veterinarian and then neutered. The testicles will 95% chance turn cancerous after a period of time. You must get him neutered to insure your dog's good health.
They can as they still have instinct even if they have been neutered.
Not all the dogs and cats that are adopted from a shelter are always neutered.
is it normal for dogs to have 4 testicles when they start to play
I don't know if there are any dog show that allow spayed and neutered dogs.
First of all no girls are neutered. Boys are neutered. Only in dogs and cats. Not people. If you have a female pet, it has been spayed, then no, its heat cycle will stop.
no
if you mean a dog being spayed or neutered, No they do not get mean, only people make dogs and cats mean!!
To prevent them from siring more puppies.