> If it was a gradual thing, that kind of sounds like a poisoning or a
> toxicity issue to me.
Mavrck, I agree. Consider the possibility of lead or zinc poisoning. I know of two birds with similar symptoms caused by zinc poisoning. One, an amazon, recovered the use of his paralyzed led after treatment. The other, a patagonian conure, still has both legs paralyzed but he has full wings and is able to fly to move from place to place.
Has your bird been chewing on metal objects? Galvanized cage wire, hardware cloth, keys, coins, stained glass ornaments, fishing (sinker) weights, costume jewelry, curtain weights, nuts and bolts, quick links, drywall, galvanized plumbing pipes? Cheap toys sometimes are made with galvanized wire, and metal bells sometimes also contain zinc or lead, especially in the clapper part. If you know your bird has been chewing on metal (anything other than stainless steel), or stripping paint off his cage before he got sick, get him tested for zinc and lead poisoning just to make sure.