I have a cockatiel for 10 years, very healthy and for some reason he started picking his feathers. Why is this happening?

Feather plucking, or feather destructive behavior, is a very common and frustrating condition in our pet birds.  There are many causes ranging from malnutrition to liver disease, internal and external parasites, separation anxiety to inappropriate pair bonding between birds and their owners.

The first step in managing feather destruction is to attempt to diagnose the underlying reason for the behavior.  A thorough physical examination with an experienced avian veterinarian is very important in tackling this condition.