Because shes old and has issues with her teeth we give her half a can of dog food mixed with a little kibble twice a day. I wondered if switching her from beef to chicken every other day for variety would screw up her stomach. I'll give it a try, Thanks.
Our Westie (Terrier) likes variety, just like I do. Our dog has some food allergy problems, But I still take some risk to switch and add. He always has some prescription Kibble, often with just water, other times I add some different mixture of quality canned food. He likes canned food, but doesn't get it every day.
Other than allergy problems, he has no problems and seems to enjoy variety.
I have often mixed brands of good quality canned food, added to the regular kibble, and not had a problem. I don't add much. Have not had any problems other than the dog may prefer one over the other.
I don't switch daily. I use up a can then use another.