Wands for Animagi

[michaelkgidlow]

No: HPFGUIDX 73140

Does a wizard need a wand to transform into his animal self? I always 
assumed that he didn't, but when I was reading the part in PoA when 
Trelawny makes her prediction, she says that the servant has 
been "chained" for twelve years. Does that mean that he couldn't 
transform for those twelve years? But when he transforms after Lupin 
becomes a werewolve, he doesn't have wand because Harry has just 
expelled it from his hand. But when we see him in the other books, it 
is not in his animal-form. I'm confused. Any insight would be 
appreciated.

Michael Gidlow