I have a 9-month old cockatiel. He weighs 83 grams. Main diet is Roudebush pellets supplemented by fresh vegetables daily, beans, millet spray, whole wheat bread.

Two days ago he began shaking his left foot and biting at his "ankle", where the skin of his foot meets the feathers of his leg. He does this every couple of minutes. The shaking is very fast, more like a jiggling spasm of the foot.   

I took him to the avian vet yesterday. She found no trauma to the foot or leg and no damaged feathers. He did not display the foot jiggling during the visit to the vet.

He is still eating. Stool is normal. He is active and not hanging out in the bottom of the cage. He is not limping. There is no swelling or discoloration of the foot. The vet did not find anything abnormal in her exam, although she said his breastbone was a little more prominent than she liked. She said if I was still concerned after a week or so to bring him back in for a blood test. I'm unsure whether I should wait that long.

Have you ever heard of anything like this? I have a video of him doing the foot shaking and nibbling if it would be helpful to see.

Customer (name blocked for privacy)@tw.mi.rr.com

Optional Information:
Age: <1; Breed: Bird/Cockatiel

Already Tried:
vet visit; bird bath; think coat of vaseline on leg.