Hi KMS
If the vet diet is eliminating all symptoms, stay on it for AT LEAST 6 weeks to allow histamines to clear out of the body, 10 weeks is better, unfortunately. Pick a limited ingredient food that you are interested in trying and copy it’s ingredient list. Stay on the vet food, but after the 6-10 weeks is up add one ingredient from the food you want to try back into his diet, example the food you want to move to has duck, sweet potato, peas… just add duck to the vet food, for 2 weeks, watching closely for a reaction. If you see one at any time, go back to just the vet diet again immediately. After 2 weeks, if you don’t see a reaction, start adding sweet potato to the diet for 2 weeks. Continue doing that until you have added the protein and starch sources from the food you want to move to and had no reaction. Then you should be able to safely use the new food, time to switch. Pick the next food and start adding it’s ingredients.
I would save the foods that are more likely to cause reactions until last, because every time your dog has a reaction, you have to put it on something you know it isn’t reacting to for 6-10 weeks before you can move on again.
If the vet food is not completely getting rid of all symptoms after 10 weeks, I would go ahead and move to a limited ingredient food that was very different. And try again to find a good starting place.
