
In the UK, I believe, rightly or not, it's felt if a mating can't be achieved the normal way, then it's not meant to be. It isn't totally banned - in breeds with a small gene pool, it is accepted/allowed (might be different now because it's been a long time since we were breeding actively). But I think you have to jump through hoops to get KC agreement. Coming from Canada, I tended to go with the idea of if it wasn't happening naturally, and the bitch was right on, then by all means collect semen and get it in where it should be. We did exactly that with a male we travelled from Toronto down to just outside Philidelphia to use. She (UK bred!) was dead keen - he was .... just NOT AMERICAN!!! In fact she got so fed up with him that she uttered a visible sigh, and sat down with her back to him. That told him about what she thought about him! The next morning we took them both to their vet who checked her, and then made a collection from him, checked it (it all seemed normal) and AI'd her. We did try again that evening but he wasn't really interested, so we came home, in hope. She had two puppies, one DOA so we went back with more success - 5 puppies. And they were good at that.
I know of many popular stud dogs in America especially who never mate their bitches naturally - to help prevent the risk of infection! It may happen in the UK, more than is admitted - but often only those involved know!