Well, just as you and I might catch a virus and have the "stomach flu" for a few days (which is not really the flu, but a misleading colloquialism), so has Buster. Poor guy spent the night with the doctor and will have another night with him to clear out his system... gross. The Doc said he didn't think we would want to deal with the mess of a squirty dog, and he needs to be observed so that he doesn't get dehydrated or anything.
But the good news is that he will live, and is already feeling better. Hooray!