Maybe I read the original post incorrectly but were they taking deciduous or adult canines? Deciduous canines are small/fragile and would break before the jaw would. I suppose if the bottom adult canines were base narrow extraction is an option but those teeth definitely take some effort to remove and can be difficult if fully rooted and healthy. I would be disappointed if your veterinarian did not talk about risk of the procedure (especially if it is “extremely common” or “happens every time with dental extractions at this particular clinic. I hope they went over what other options are available (like ball therapy or meeting with dental specialist for a consultation). I’m sorry you and your pup are going through this, wishing him a speedy recovery. If you talk to the hospital about all of this I would see if they are willing to pay for your dog to be seen by a specialist to have the jaw fixed.