I'm thinking of switching our dog's food from Iams to Blue Buffalo. The problem is, I switched him to a new food 1 1/2 years ago and had issues. Henry was fine for a few months and then he started throwing up a couple times a day. The vet suggested some medicine, but it didn't work. After looking up his problems online, we switched back to the old food and gave him smaller meals several times a day. He got better and we were eventually able to go back to feeding him twice a day. I'm worried if I switch his food, even slowly, he'll get sick again. He didn't get sick for a while after we switched food. What do you guys think?