All the dogs in the past 35 to 40 years that I have been involved with have been co-owned for a variety of reasons. The co-owners have been my spouse, my daughter, my training partners. You have what is called the primary owner, first name on the registration, and then the others thereafter. My present co-ownerships are a three way with a Derby Dog now on the National Derby List, the primary is not a dog trainer, the other two are, including myself, A MH three way co-ownership, primary is not a dog trainer. My three at my home dogs, two my daughter co-owns and the third my spouse co-owns with me. Also, co-own a nice hunting dog, three way, that the primary owner put my name on the registration for ? I did co-own a National Derby List dog that later became a FC, but, at my request chose to take my name off for personal reasons when the dog was about three years old. It is not like buying a car or a house, it is a name only thing for the most part but ,what arrangements you make outside the parameters of the agreement.
It has all worked out for me, including owning 6 field champions (four that myself and co-owners signed off on) and various almost dogs over the years. What one has to learn is to stuff any "big egos" in the closet, and whoever is the "new owner or co-owner" , takes the credit , so all you have is self satisfaction that you were involved at various points in training, running, etc. that to me is the biggest obstacle. There are several "horror stories" of some dogs co-owned became very bitter issues as they gained fame. Overall I think co-ownerships are good things for sharing expenses, even including professional training fees.