Our 12 year old Sheltie recently died of acute renal failure. She had a bladder stone 10 years ago and has been on Royal Canin Urinary SO for 10 years with no urinary problems. But a month ago, at her annual, our Vet did bloodwork and found her BUN and Creatine were extremely high and she had a urinary infection, which the Emergency Room Vet said may have exacerbated the problem. I saw in the web that Royal Canin changed their formula in 2020 and am wondering if this could have caused the urinary infection. Has anyone else had a problem with kidney failure while on the SO food?