Check if its not posible to go to the vet more often for positive reinforcement training, just geting used to the travel and being there without going in to an apointment. Then go back home. A good vet will work with any owner to reduce stress in animals, many animals do feel stressed going to the vet if they only do it once a year to be proded and poked. Going to that place going in for 5 min or so do a bit target or something, with good treats and such, gives them a positive assosiation and might make it less stressfull when the animal is sick (and therefor often already stressed).