stud problems?

Question
What would cause a stud to not mount the bitch when she is presenting herself to him repeatedly?

Answer
Hi Mark:

There could be a number of factors. If he's too young he may simply not be mature enough to have the instinct to mate. He may be reluctant to mate if he's had a bad experience with a female in the past & is too passive toward them. Of course, there are also a myriad of physical possibilities, such as hormonal imbalance or similar situation. I wish I could provide a more clear-cut answer for you but the best advice I can provide would be to have your vet conduct some pre-breeding testing to see if anything is awry & that may shed some light onto his lack of interest.