Hello, welcome to EBN. You just mentioned your problem, Royal Canin!
You will be visiting more and more your vet if you donāt get your dog off that brand. A lot of other members ask the same question as your dog, 75% we see dogs are on Royal Canin, Science Hill, Purina, Iams, etc. they are all kibbles full of grains. If you canāt do a raw diet and want to continue with kibbles, look into Zignature, Fromm, Acanaā¦. Also buy raw liver at your grocery store, cut in small pieces, use about 1/4 cup per day for the first week ish then 1/2 cup daily. It will build his immune system. Use it as a topper. You can also use a couple tablespoons of either/or fermented sauerkraut from the fridge section, goats milk, Kefirā¦ā¦but do get off that kibble immediately. Read in the form about kibbles and you will see itās not recommended. Also buy marrow bones as attached photos. Give it raw. It will keep him busy while building his gut flora.