We have a 7 month old puppy, half Dachshund and half Jack Russell terrier. He looks like a Dachshund on steroids. Glossy red coat, bright eyes, lots of energy... maybe too much. He gets hiccups often, once or twice a day, and for the past 4 mornings, he vomits yellow frothy liquid. He doesn't want to eat his morning meal and eats his evening meal, but is really lacking enthusiasm for it. We feed a combination of Purina puppy chow with a bit of canned food added (a good quality IAMS equivalent) just for flavor. Before we got him he lived with a family that most likely fed him junk food from their table and maybe he's habituated to greasy hot dogs and chips. None-the-less, I don't understand what we could be doing wrong, we need help.

Your regimen sounds much healthier than table scraps. I am not sure what is wrong. Maybe best to let a vet check him. May as well have a heart worm check and get him started before the mosquitos come out.

Don't let anyone feed you any nonsense about problems from the Purina. I raised a number of healthy dogs on it. Biggest advantage of the more expensive chows, is the smaller, easier to clean up stools.