Canine Stomach Problem

Question
My question is in regards to my 3 year-old Rottweiler, Maximus. Since he was about 1-year old, he has suffered from periodic bouts of vomitting for no apparant reason. About once every few months he would begin to salivate excessively, eat grass voraciously and then finally expel his stomach contents. The bouts usually lasted about 2-3 days and then he was fine. The veterinarian that we went to just attributed this to a "weak system" and told us to only feed him dog food, no scraps etc. He was also treated with antibiotics for collitis about a year ago. During that time he lost a considerable amount of weight.  

Recently we moved to Germany and Max accompanied us but since we arrived the bouts have come closer and closer together, every few weeks or so. The vet here (military) is not very helpful with the problem, they think it is dietary but I swear that we do not feed him anything but dog food (IAMS). He has not lost any weight and he seems to be perfectly healthy in between episodes but I just wonder if there could be a deeper cause to his problem and if we should search for an outside veterinarian, or are there some dietary options that we should look into? Any suggestions you could give us would be greatly appreciated as we are so tired of seeing Maximus suffer.  

Answer
I would definitely try a diet change to something more natural.  I do not know what food brands are available in Germany, but look for a food with meat as the first ingredient, no meat by-products, no dyes, no preservatives, human-grade ingredients are ideal and also if possible try to stick to a food without corn or soy.   Some of the food companies that I recommend people try from the States are Verus, Innova, Nutro Natural, Natural Balance, Solid Gold, Wellness, Eagle Pack.

In addition, I would recommend adding digestive enzymes to his food as well as probiotics.  A pet product called PROZYME is an inexpensive pet enzyme supplement and for probiotics you can simply give yogurt.  Alternatively, you can purchase a human combination product at a health food store and give him the labeled adult dose.

I would recommend some blood work to rule out any underlying kidney or liver disease as well as checking his electrolytes to rule out Addison's Disease.  You could also have his stool sent to the lab for a culture.  Otherwise if the problems persists, you may want to consider going to an internal medicine specialist and having a endoscopy done to get some stomach and intestinal biopsies.