Check out Town and Country in Windsor, right off #3 highway.
Dr. Fetherstone is amazing and if you discuss your concerns with him and the reason why you are opting for the vasectomy he will have some great information for you(great choice! as my male will remain intact but if I ever do decided to stop his ability to reproduce it will be through this method instead of a neuter).
There are also cons to the health and development to those neutered.
I perfer to leave my male intact but think that a vascetomy is something worth checking into.
Behavioural changes in dogs that are neutered is something of a controversial topic, is it really due to lack of hormones or is it maturity and training? Personality/Genetics? What is someone is satisfied with their dogs behaviour? If someone is looking at it from a health point of view then definitely a vasectomy is something to take into account.
No, he didn't say specifically why it wasn't always effective, he just said that he wasn't doing them anymore. I imagine there were some complaints from people who may not have understood the difference between vasectomy and castration. I'm going to see if I can find a vet that will do it, I think I'd rather have that done.