1. Hours. My vet practice is open 7 days a week, ~7am-7pm. They also have weekend hours. This means I can go there any time, which is particularly important when Teddy is having food problems, since he uses prescription diets.
2. Number of vets. While each of my cats sees a different vet, there are a total of 6 at the practice. This means that even when my cats' vets aren't available, I know they will be seen by someone who has access to their regular vets, and also their records.
3. Drop off services with no charge. PJ gets her blood checked every few months. If they can't get to her right away, I can leave her for a few hours and she has a clean cage, is provided with food and water, and we aren't charged a thing - just for the blood work.
4. The vets must be willing to take questions - not just in person. Because of the medical management for both my cats, I always have questions. Every time we change Teddy's prednisolone, I talk to the vet, and she talks to me. When we don't connect, she'll always call back later or leave a message, and she doesn't mind that I can a ton of times - mostly out of paranoia.