C.D.
Companion Dog: A suffix used with the name of a dog that has been recorded a Companion Dog by the AKC as a result of having won certain minimum scores in Novice Classes at a specified number of AKC licensed or member obedience trials.
C.D.X
Companion Dog Excellent: Similar to a C.D. only with the result of having won certain minimum scores in the Open Classes for obedience trials.
C.G.
Certificate Of Gameness: An award given by the A.W.T.A ( American Working Terrier Association) which can be compared to the AKC's Senior Earth Dog Title. This title is given after the dog completes the junior and can then compete for it's Masters. An Earth Dog trial is where a terrier is tested on it's skills in hunting a quarry under the earth.