Hello Lynn, i don't know if you are still in this forum since this is quite an old post, i am going through the same nightmare with my cockatiel (Cleo), and am going tomorrow to the vet to see if it is giardia that Cleo might have. I wanted to know if Squeaky got well, and i am sorry for my ignorant question but, what species is Squeaky?
Cleo doesn't pluck his feathers, but he does scratch his skin underneath a lot and sometimes causes sore spots even wounds, an every now and then a countour feather "falls" due to scratching but he doesnt pluck them. he does it on his back (between his wings) and under his left wing. His poops look normal. He got treated with baytril(antibiotics) and now is getting aloe baths and antiseptic (safe ones) on his skin, we also used propoils on him, he also got treated for mites but it didn't solve the problem, it does weem that when he is wet (after aloe) it eases his itch, but when he starts getting dry he starts scratching again. He was also collared.
Thank you so much in advance. Daniela