D) Please don't let your dog walk around and pee on everything:
You might think that it's cute and acceptable to let your dog wee and poop on the floor, but I can assure you, clinics don't. Absolutely, accidents do happen: a lot of dogs go to the toilet and/or vomit in vet clinics (it's all of those lovely doggy smells) and we are happy to clean up after them. Please, just don't let them wander freely about the waiting room cocking their leg on everything. It drives us balmy (cos then every other male dog comes along and wees in the same spot!) Keep them on a lead and away from vertical surfaces and the problem won't occur.
In addition, if your pet does happen to have an accident, please don't be embarrassed about it and keep it to yourself. If there is feces, vomit or urine around, please tell someone on the clinic staff so they can clean it up. Urine, stools and vomit has the potential to spread disease and, in addition to this, vet clinics are potentially liable if someone slips over and cracks their skull on the floor.