I would see if the current owner of the Chesapeake would have any problems if you talked to the Vet that diagnosed this condition and see just how many test they did to come up with the answer to why the dog has the skin problem.There may be more than one type, or place to purchase food that would work for the dog. You can also post this question on the Team Chesapeake sight on the "Brown Dog Chat" section. This sight can also answer any questions you might have about the breed.
http://teamchesapeake.com/
