it could be a sign that he may have a tumor, check up with the vet and get a seconed opinion
No.
go see your doctor! you could have a tumor or some other abnormal groth in your testicles. i am sorry if this has happened to you. life must suck for you and your partner if you even have one.
If it really is one of the testicles, then it isn't normal. that would be a failed neutering. The dog would still have all the urges of an intact dog, and still be able to father puppies.
All male dogs have two testicles. In some dogs however, only one testicle forms and at times there are two but only one has descended into the scrotum. To be sure what is going on with a male dog which appears to have only one testicle, have it checked by a veterinarian.
It is not normal for one side of the testicles to be numb.
Most often a bump on a testicle is a cyst, called a varicocoele, which is harmless. However it could be more serious and its important to have a doctor check it out.
The dog has an injury probably got while playing.
you would have three testicles in one scrotum.
This happens quite often where one or both testicles do not descend. Normally your dog does have both testicles but one is retained up inside of the abdomen. It can be genetic so do not breed a dog that this happens to. Do neuter your dog as soon as your Veterinarian says it is ok to do so. It is important as the testicle that is still retained up inside of the abdomen will most likely become cancerous in time. Please have your Veterinarian check your dog over first for his opinion.
He's not asking about the Train song but the one that sounds like Rehab Badah bump bump bump badah bump bump bump bump
This will depend upon the exact state of the testicles. If both testicles are retained within the body wall, the dog will be infertile and produce no viable sperm. If only one testicle is retained within the body wall and the other has descended into the scrotum, the dog will produce viable sperm but likely have a low sperm count. If only one testicle is retained but it is outside the body wall although not in the scrotum, the dog will produce viable sperm and may have a normal sperm count. However, cryptorchidism (retained testicles) is a highly inherited condition, and it is likely that the dog would pass this defect on to his offspring. For this reason, most veterinarians and responsible breeders will advocate for the dog to be castrated and removed from the breeding pool.
A bump in your back could be a bug bite or a small tumor. If you are feeling tired and noticing bumps on your back, you could have one of a variety of ailments including cancer. Check with your physician as soon as possible.