This can happen when the dog experiences something that frightens them, such as when they receive those first puppy shots or have had to have a procedure that made them apprehensive.
You'll notice the next time they realize they're going to the vet's office, they'll show anxiety by refusing to budge, run and hide, or they may shiver and shake, whine or bark at you as you try to unsuccessfully get them to follow your lead. Pulling on the leash is not an option as you can injure your dog by doing so. Here are some tips that may help you to ease your dog back into the vet's office after a traumatic visit.
Call ahead of time and request an appointment if at all possible when the waiting room will be "not so noisy", so as an early appointment or the last appointment of the day.
Always contain your dog, by using a good sturdy leash and collar, or a carrier if the dog is small.
Bring along your dog's favorite treats to use to coax your dog to comply with your commands and to reward your dog for doing as you have asked.
Sit in the corner away from the door leading into the waiting room so that your dog won't be startled by new arrivals into the room (human and animal).
Make sure you can get in and out of the vet's office quickly by preparing ahead of time and having all medical records, shot records, medication lists etc., with you or at the vet's before your appointment.
If this is a new vet, take the dog to the vet's office before the appointment, just to meet the staff and let the dog become accustomed to the place, and the smells that the dog will come into contact with before the day of the appointment.
Visit the vet on a regular basis so that the dog will become familiar with the vet. An emergency trip is not the time to get to know a new vet. It is better to allow your dog to get used to a vet when he/she is not already fearful or in pain.
Your dog will do better in the waiting room of the vet's office if your dog has already been socialized with other dogs, cats, and other animals that your dog may be exposed to while waiting at the vet's office.
Make sure you get your dog used to other animals by bringing your dog to a park (on a leash) or other place where dogs are likely to congregate with their owners.
If you have friendly dogs and owners in your neighborhood you might consider having a dog party. Invite the dogs and their owners over for an outdoor party. You'll be able to witness your dog's ability to cope with other dogs in a safe environment before taking them into territory that is not as familiar as home. If you notice problems occurring, you can address them with your vet before the day of your appointment. Your vet or the vet's staff can give you ideas of how to make the vet's visit safe, and as enjoyable as possible for your dog and for you.