Hi Carrie R,
Have you tried her on a grain free salmon? The food you are currently feeding has grains. I have a dog that can’t tolerate any grains and as she got older developed an allergy to 1 specific protein.
https://www.proplan.com/dogs/products/focus-adult-sensitive-skin-stomach-formula/#ingredientsandguaranteedanalysis
Zignature has 2 fish formulas that are limited ingredients that might work. It could be the protein (fish) causing the allergy, but I would try eliminating the grains first. If that doesn’t work, I would switch to a new protein she hasn’t had. It could be environmental as well, but I would try a limited ingredient diet first. If you do this, you need to make sure ALL the treats are the same protein and grain free otherwise you won’t know if it’s working.
