I recently had to change Dukes food because of some abnormal blood results which the vet is thinking is just from a food allergy. So anyways I put him on California Natural Herring and Sweet Potatoe. This way I cancelled out anything and everything that could have possibly triggered a food allergy. (Im still not convinced it is a food allergy but thats awhole other topic) What I want to know that since he is on a fish diet now is there any vitamins/suppliments I should be adding into his diet because there is no more meat in it. Im not to knowledgable on food so I just want to be sure nothing is being missed in his diet that is needed.