My canary has stopped moving about his cage. His appetite is down, he has stopped singing and plucks at his feathers and fluffs them a lot.He still eats but not as much, and does not sit as upright as usual. He has also taken to sitting on the floor of his cage which is unusual for him. Is he just old or is he sick?

Optional Information:
Age: 7; Male; Breed: canary

Already Tried:
vitamins, varied diet.