My Dog Is Pacing And Cant Seem To Get Comfortable.

My dog is pacing and cant seem to get comfortable. He is letting out yelps periodically. He is off his food but is drinking water. He is also chewing his paws. This seems to be an ongoing issue for the last 2 years and lasts a day. I have changed his diet from pet food to boiled chicken and either rice or pasta.
My dog is a foxy poodle and is 4 years old.