I went to
www.canada411.com and searched by category (Finad a Business/Family& Community/Pet Services/Pet Training - and then you put in the city you're looking for). There were quite a few obedience schools in and around Montreal. Unfortunately, none were listed directly in Chateauguay. I'd suggest finding some that you're comfortable travelling to and paying them a visit first without your dogs. I know of one in Lachine who was quite punitive in his training methods (but that was 13 years ago and he might have changed his tune by now, so I'll let you visit him if you want and judge for yourself
). Good luck!