I have an 8 year old male dog. Four years ago he mate well but since them he has had one testcle out. We had him with a bitch but all he's doing is licking her and not mounting her. Any ideas?

why are you breeding from a one testicle dog?

Under what circumstances was the testicle removed?

The bitch may not be ready or he may have low Libido with advancing age.

What was the reason his other testicle was removed?