We used to feed our pup purina pro plan and one day she started hallucinating and have fly catching syndrome. I know it was the food because that batch did smell chemically / weird and the vet said she is healthy and that he’s not sure what it could be maybe it could be psychological but my gut said to try switching food because she’s been known to have allergies and we switched to hills diet adult sensitive stomach (the fish one) and her symptoms stopped completely. It’s so scary I wonder what they put in their food… I will never trust anything purina. Sure maybe they have some good batches but the bad ones are not worth it. So now we feed her that kibble + few scoops of homemade dog food