Any advice on food that is low in fat / protein

I have an 11 month old English Setter who has a Mega Esophagus and am trying to find a good quality food lower in fat and protein.

Hello and welcome to the forum. Your post is very brief with no information except for the diagnosis. Are you wanting help choosing a suitable product? Please can you give us some information about your dog? What is he currently having and what are his symptoms? What kind of diet has the vet suggested? What percentage of protein/fat are you wanting?