Ferrets will still grow until they are about a year old, but by 6 months
old they are usually already at 90% of what their adult size will be.
Also, as for altered males, I've heard that they can get up to 5 pounds,
but more common is 3 - 3 1/2 pounds.
 
Shannon, Sterling, Pandora, & Jasmin
[Posted in FML issue 3510]