What do judges test for a dog in a dog show?

"conformation"The body overseeing the show (such as the Kennel Club, AKC, etc) will publish a set of (fairly arbitrary) standards, which define what makes a "perfect" specimen of the breed.Size, weight, colour, markings, eyes, tongue, nose, right down to tiny details... then there's how it moves, how it behaves, how it reacts to stimuli.The judges "score" the dog on how close it meets the standards... In turn, the people showing the dogs train them to move, stand and behave in the "right" ways, and the breeders manipulate the breeding programme to eliminate "undesirables".It's all completely artificial, but there's a lot of money involved, so it goes on.

They test its grooming, health, shape, weight and how it is trained.

I will say IanP's post was way off, Helly has a good post of explaining how things work. So I won't sit here and type it all out again, but thats pretty much it.

You can't groom, train or walk faults out. Training is also good, and should be done anyway, grooming presents a nice dog instead of one that is dirty, mangy, matted or uncared for and should again be done anyway and you can have a dog gait at a certain speed and teach it to heel but you can't make it walk to hide a major fault/health/structore problem.

They also try to look at and judge temperament, which isn't totally possible, its not a temperament test, but if the dog has shyness, isn't social or acts skittish that tells you something about the dog.