I have a male westie 1 year old. Our in-laws have a 2 1/2 year old westie bitch who is in season.  When he got the scent of their clothes he went crazy peeing and howling like mad, we met them at the park a few days later and kept them close by and he wasn't interested in her at all he had a quick sniff then walked away but she kept trying to hump him why is this? He has a retained testicle and is going in next month for the operation could this be why?  could anyone advise me on what to do regarding operation is it better to get him fully castrated at the time or leave him with one testicle and do they still go mad at the scent when they are castrated or does it not bother them. Any help gratefully received.

If he has a retained testicle don't allow him to mate. It is a genetic fault which he could pass on.

Regards, John

Even castrated dogs get interested in the scent of a bitch in season, maybe the level  depends on what age they were castrated at. Mine was done early so he follows the scent avidly but dosent seem to know why, he just looks confused. Been told here though that a castrate dog will try to mate a bitch and can tie with her.