I have a very good relationship with an avian vet who told me that is the cause in most cases. Sometimes it is a result of mites,etc.
If this is the cause in most cases, then it is a good thing that Petco isn't selling these disease and parasite-ridden animals as pets any more, isn't it?
To take it one step further, why would Petco start breeding and selling these disease and parasite-ridden animals in the first place?
This shows no concern for either the animal or the new owner because there are bird diseases like parrot fever which can be transferred to humans and if this is the cause as he asserts, then this is irresponsible on Petco's part.
Wouldn't you agree?