2nd answer:
The testicles can swell up due to an infection. You should take your dog in to be checked out by your Veterinarian as this condition is very painful to your dog.
1st stupid answer:
U PERV!
when they see a puppy vagina
Iam going to take a guess at this because I believe I had this similar experience with a neutered bassest hound. I say a guess because I can not visually see your dog. Is the swollen area present all the time or only some of the time? Is the swelling located on the side or both sides penile shaft and not where the srotum is or was located? If all this is true and you only see the swelling at times then chances are your male dog is sexually aroused. If he is happy and playful, filled with excitment to see you and/or just enjoying a petting session with you then chances are he is aroused. Can't tell you why they respond with sexual arousal only that they do. If the swelling is constantly present then it may be a good idea to see a Vet, could be a sign of infection or magligancy.
Horses are not immune to testicular cancer, so that may be the main reason behind abnormal swelling. If the horse does not seem concerned by it or does not protest when his testicles are handled, it could mean that his sperm production is in overdrive, which can be solved by having him copulate with a mare.
maybe he has a stone
These are one of the cues that indicate a dog is in heat.
I believe in the testicles.
When it get swollen it might be that she is pregnet
Vasectomy means severing the ducts leading from the testicles, but leaving the testicles in place. Means the dog can't father any puppies, but will keep all the behaviour parts of being male, like aggression. Castration or neutering means removing the testicles entirely. W/o testicles the dog's testosterone levels will drop, making the dog less aggressive and less challenging.
No. Only two testicles.
Take the dog to a vet, they could tell you.
Your gonna have to feed the pups yourself if you don't your pups will die. If the dogs breast are swollen then your dog is sick.
Take it to the vet.
Pregnant?
If the dog's eye is swollen then you need to look for redness, discharge or other signs of infection or trama. If it does not resolve in a day or two I would take the dog to the vet.
call the vet