Find a veterinary team that wants to spend time with you and one that focuses on prevention. Nutritional advice is often overlooked. Find a vet that your pet feels comfortable with. Pets are often reluctant to be examined at a vets to begin with.
Ask your vet about positive reinforcement visits, if your pet is anxious at the vet's, it is likely to get worse without positive reinforcement and desensitisation. If pets are unable to be examined due to fear aggression it can greatly diminish the care that can be provided and also stress is counterproductive to healing. Do not let your pet's fear jeopardise its health. Visit your vets more regularly and reward positive behaviour.