My dog was diagnosed with Chronic Kidney Disorder almost a year ago. Since then, I've been giving him Royal Canin Renal food and Ipakitine powder. Everything was normal until couple weeks ago when his left side of the face swollen, but we've treated that as well. Now, he refuses to eat the food, but he would eat anything else I give him. He didn't eat for a day, and he still doesn't want to eat it. Any advice on what should I do?