@tanza:
That said, if he has been fine on it, then I would wonder if they have changed the process of that food.
+1…If I had to guess, they either changed processes or ingredients if he's been fine on it before. There have been 2 different times I've changed foods because my b's changed reaction to it.
Once was with Timberwolf. I purchased a new bag (had been using it for 2 -3 months successfully) and Brando refused to eat any food from the new bag. I asked about it where I bought it and found out that they had changed it and added chicken fat to their fish based food. I threw the bag out and switched to a different brand of food. Also, the pet store I bought the food at stopped carrying Timberwolf because other households had the same issue and they didn't like the ingredient change without the company informing the retailers.
Another time was with Wellness Core...both Ruby & Brando started losing weight on it after a new bag was purchased - previously they had done great on it...I threw that out and switched brands.