What causes a budgies cere to collapse?

Question

I was in a pet store recently and some of the budgies seemed to have collapsed/caved in ceres. It looked really awful for the birds, I'm sure they must have had trouble breathing.

They were both males and females and housed in an aviary.

Any idea what could have caused this?

Answer 1

I have no clue but that sounds absolutely awful!!!!

Answer 2

It´s possible due to burrowing mites. they attack any kind of  parrots, specially budgies.

Check this link:

http://www.birds-online.de/gesundheit/ge...

please tell the pet store manager to ask to a vet to give an appropriate treatment to the birds because it could be mortal.