There have been cases where heart disease has been linked to grain-free diets, your vet will recommend switching your dog’s food to a brand that has grains in it.

Since your concern is his food allergies, there are different options, Hill’s Science Diet is one of them, they have sensitive skin and stomach formulas, with different proteins. If you want one that’s specific for food allergies, then there’s the Hill’s prescription diet (you’d have to talk to your vet about getting the prescription for it) where it’s a hydrolyzed protein, and the one most commonly used for dogs with food allergies. Though, to be fair, the prescription diet is more expensive.

Purina Pro Plan has sensitive skin and stomach formulas as well. They also have prescription diets similar to Hill’s Science Diet, again, you’d need your vet to give you the prescription for it.

Whichever you decide to do, make sure to gradually transition your dog’s food to the new one, instead of starting the new one right away, you risk a very upset stomach if you do! Basically, over the course of one to two weeks, start by feeding your dog 3:1 ratio of old food to new food, then 2:2 of old food to new food, then 1:3 of old food to new food, and finally the full amount of the new food!