I took Hunter to the vets today for her annual check up and shots. Usually when we go she is very happy and excited and cooperates rather well. Today however she was whining and shaking and very wary. Nothing has changed. Same vet, same office even the same room. Nothing else was off in the past few days. She was back to her normal beagle self when we got home. Do you think she was just having an off day? Any ideas? She is six now and maybe just decided that today she didn't want to be there?