Someone needs to tell my dogs about this food allergy stuff. My previous dog was on the same food 10.5 years. The current ones 2 and 2.5 yrs and counting. No food allergies, or any other food disturbances.

Reactions our puppies have to their dog food comes in two forms:

1. True allergic reactions due to one or more ingredients in the food.

The dog encounters the allergen the first time and has little or no response to it. The next time and thereafter more severe allergic reactions will occur. It might be possible for other factors to induce food allergies where previously there was no reaction. For example parasitic reactions might in general raise IgE levels that trigger against the food. In general though a true allergic reaction to food is genetically based. The dog will either be prone to develop the allergy or will not. In essense an allergy is due to an over reactive immune system based on the genetics of the individual dog. The dog food I feed is primarly chicken and corn meal along with about 10-15 other items mixed in (e.g. eggs, various supplements). If I had a dog that had a genetic tendency towards allergies then it might be possible they would be allergic to something in this brand of food. The point being it doesn't matter if they eat this same food the rest of their lives or not- after two years with no allergic reactions the probability they will develop one now to this food is extremely small. The genetics just are not there.

2. Non-allergic reactions which are primarly centered around digestibility of the food.

Your dog may not be able to tolerate the type of filler be it cornmeal or wheat from a digestive post of view. Or the pancreatic enzymes the dog produces may not be able to break down the particular meat component. A dog that suddenly reacts in an "allergic" way to their food after being on it for some time, is probably having a non-allergic reaction to it. With aging alone the digestive systems of some dogs will dramatically change. Also note that whenever you "change" the basic composition of the food, you are also asking the dog's digestive system to change. Switching brands is inviting this type of reaction to occur, and thus the need to change gradually. My philosophy is switch only if you have to, as it's less disruptive to the dog's digestive system.