Lugnut, I was at Conservation Station yesterday, too, and got the same answer. No more vet procedures on Wednesdays. We went out there right after the park opened yesterday, and I was disappointed! I had a nice discussion with the CM at the animal nutrition station, but then ran out of things to do. I wasn't able to go back early today due to a mid-morning ADR, so I missed out on the vet procedures this trip. Bummer.
One other fun thing to do, though, is to catch the presentations at the small "animal encounter" stage next to Affection Section. I caught part of the show, where they brought out a spectacled owl and talked about her. That can be quite fun and very informative! They do these presentations three or four times a day. In the past, I've seen several birds, a hedgehog, a porcupine, and other mall animals.