Hunter had been acting like a regular beagle all day yesterday. Ate breakfast and supper, we went for a walk, she played with Casey, no problems. Mike came home from work and she wouldn't get up to see him. He had supper and she didn't go to see what it was.She always tries to check it out. He called her to him and she whimpered every time she moved. We checked her all over to see what was hurting and determined it was her back end by her tail and hips. I called my vet which was opened late, and they said to bring her in in the morning and if anything got worse to take her to emergency. When she started to shiver we took her in. When they examined her there he thought it could be a slipped disk in her spine. I told them I had an appointment with my vet the next day and so he sent us home with some pain meds and instructions to keep her in comfortable and quite. So when I am at our vet appointment they do an x-ray to rule out a slipped disk and the x-ray came back fine. The Dr. had checked her out and drained her anal glands which were infected and full, and that was causing her pain. Now she wasn't scooching, or licking or showing any signs of discomfort until last night. Everything was all normal. I was angry at myself for not noticing, but I don't know what else to look for. The vet said that sometimes there are no signs until they are in pain. Anyone else have some advice? She is doing fine now and on antibiotics for the infection and pain meds. What did I miss?