I used to mix brands of food with no issue for about 8 months or so, but then I realized that I am reducing variety for my dog rather than increasing it. For example, I had mixed Blue Buffalo Wilderness with Holistic Health Extension (both chicken/turkey based), then I had mixed Dr. Tim’s Kinesis with Nutrisca Chicken and Holistic Health Extension GF (all chicken-based), then I fed some other mix I don’t remember, and then I fed Earthborn Coastal Catch mixed with Victor Yukon Salmon and Holistic Health Extension. The thing is, with my small dog, the mixes were lasting forever, so storing them properly was a mild concern (I would keep the mixes sealed in the bags they came from), but I also wasn’t giving much flavor and variety as Bruno would eat the same mix (which he saw as his one type of food, even if it were 2-3 mixed together – he didn’t taste or know that) for a long time. So I just feed one bag at a time for variety and easier storage of the food.
I do, however, have a friend who also mixes, and she does it kind of for the same reason – she would get a 3-ish star-rated food and mix with a higher-quality kibble. Her dogs have no issues and burn through foods pretty quickly seen as she has 5 of them. She is also pretty good with watching expiration dates and remembering what she’s mixed and storing the leftovers properly. So you COULD technically do it if you need to.
