
A lot of male puppies have retained testicles until they are a year old & there is no need to remove the retained one until the puppy is a lot older
As to wanting to breed from your dog he should not be bred from before he has been X rayed & scored for HD & been tested for haemophillia
If the testicle does not descend you should not breed from him & you should tell the breeder & his mother should not be bred from again as she is the carrier of the gene for testicles