Hi Denis,
Look into feeding Freeze Dried raw..
“Buckley Liberty” formula’s came 1st, 2nd 3rd & 4th when 299 best selling dog foods were tested for Heavy Metals, Contaminates & Toxins, these dog foods are tested every 3-4 months & Buckley has stayed on top..
https://buckleypet.com/collections/all/products/liberty-fresh-dry-food-for-dogs
Also look at “Stella & Chewy”
https://www.stellaandchewys.com/raw-feeding/what-is-right-for-you/
Start rotating between a few good brands, never just feed the same brand of dog food, this is when the dog can start to react to an ingredient.
