Dog afraid of the veterinarian
Fear is often an underlying cause of aggression at the vet and it is very frustrating for all when a pet is unco-operative. I think we have a situation here of firstly the breed characteristics of a Chow, notoriously aggressive at the Vet, and secondly you need to get the fear somewhat controlled.
A very common solution is to sedate Dakota with tranquilizers prior to the vet's visit. Another option is to consider a mobile vet since it may just be a fear of the premises at the vet and if he is generally friendly to others, he may allow you or another vet to apply a muzzle at your home situation.
I would suggest you practice applying a muzzle at home without anything happening to him before you take it off so he doesn't associate the muzzle with something bad always.
Lastly, I would strongly suggest he get neutered if hasn't already been neutered as this will control male aggressive tendencies.
Good luck. I know it is frustrating.
Martin Slome DVM
Centre Street Animal Hospital
7700 Bathurst Street Units 40-42
Tel. (905) 771-9855
Fax (905) 771-7260