Pictures Plucking or something more medical?

[PeppysPal]

I think you are wise to take the bird to the vet. If you can save all of the feathers he has lost and take them with you, it would be helpful.

Calcium deficiency is a big problem with Greys. Has he been getting plenty of calcium and direct sunshine (not filtered by glass)?

That's one of the things he's testing for I believe.

 

[Hankmacaw]

If he doesn't offer to test for calcium (it will show in a Chem panel) be sure you ask for a CBC and a Chem panel - it all starts from those two tests.