Cindy's Answer

If I had a monorchid I think when the dog was mature I would have the retained testicle removed and leave the descended one. I've had two friends with dogs recently experience testicular torsion with a retained testicle and it almost cost their dogs their life. One of my friends did not even know the dog had a retained testicle, he was adopted from a shelter and was supposedly "neutered"

Both of my friends' dogs were between 8-10 years old and the surgery was hard on them and expensive. I might opt to do it when the dog was younger and more likely to easily bounce back from a surgical procedure. I guess abdominal ultrasounds would be a good idea too but I think if it was my dog I'd have the retained testicle removed in 2 or 3 years.