Can I ask why you think that a petstore bird can bring "all kinds of diseases?" I'm a manager at a national chain petstore and I've never had an issue with any of our birds.

It's just something I'm paranoid about. The bird is at Petco and you know how they keep all birds in the same room. Not everyone at Petco are truly qualified to work with animals or know much about them. With constant rotation of birds (as new shipments arrive) who knows what the birds are exposed to and if people(both employees and customers looking at birds) wash their hands after touching/cleaning cage/feeding each bird. It's nothing against the store itself, although I have reported Petco(different ones) for various violations/abuse in the past.
My green cheek(knock on wood) has never had any medical issues in his whole life and I want to keep it that way. With new animals, there's always a risk of bringing something in. It's true for every animal, not just birds.
Diseases and parasites are a small concern of bringing a new bird into a house. Quarantine can prevent the possibility. I"m more concerned with introductions failing or other behavioral issues that it can pose.

I think a vet visit and then quarantine for a new bird would be a good idea.
I don't know how introductions would work without cages to seperate them at first. I also don't know if it would be possible to safely keep a jenday uncaged all day, if that is what you're planning. I have a GCC who is out during the day, but a jenday is a harder chewer and you might have problems with him chewing on furniture or electrical cords. (Also, Jendays are much louder than GCC's so you have to be prepared for that).
Anyway, it is hard to know how your GCC will react to a new bird. He may be very jealous, or he may be a little nervous and unsure. He will probably not welcome another bird right away, and he may or may not learn to enjoy having another bird around. I know of someone who had a greencheek and jenday who were best friends, but they were both birds who had been around other birds most of their lives. When you are dealing with birds who have been 'only birds' for years, it is hard to know how they'll react.
If you get the jenday, you want to introduce them carefully, in the room the jenday was quarantined in (so your GCC will be less territorial) and just see how they go... but do not leave them together unsupervised in the same room until you have a really good idea of how they will interact.

Karen
Chico (conure) and Pippin (budgie)
WI

OK since it was brought up. I am a manager at PetCo. I can tell you how it works, and some info about PetCo in general.

First off, every member of management is required to be certified in all 4 of the live animal departments (Small Animal, Reptile, Aquatics and Birds). That's not to say that we are "experts" in all 4 areas. Personally I know about all 4 areas, but of the 4 the bird area is the one that I know the most about. As for the associates there should be at least 1 Companion Animal Specialist for each department....in our district everyone in the store must be certified in 1 of the 4 areas. Most of my employees are certified in 2 or more areas. If the manager on duty doesn't have an answer to a question you have, ask them when the bird specialist is going to be in.

At any point when someone touches an animal I always have them sanitize their hands for the safety of the animal (it's something that is a procedure in our animal handling).

I am curious as to the "abuse" you are speaking of at the PetCo you're talking about. Again only speaking from my corporate knowledge and our store in particular.....there is a mandatory walk that we must do every hour of the day. The associates and managers both do the walks. We check for the obvious food and water, but we also check the over all health of the animals. If at any point in the day there is an animal that is found that needs attention they are set up in a habitat and taken to the vet with in 24 hours.

If the bird is at PetCo there's a great chance that that store hand fed the bird and before it came in it was tested for disease (there should be a sign advising of such on the black c-channel where the photo label card is under that particular bird).

I'm sorry I sound like I'm ranting but animal care is the top priority at PetCo (yes even before the customers). I know that each district is different and there are some stores that could have issues but again in our district (and my store in particular) I take great pride in our animal care. Our store actually was just recognized at our national trade show for the best animal care in the company.

Karen, thanks for your input. I"m still considering getting that bird, but I'm leaning towards not to...My Iago is my first priority and I don't want to complicate things or bring unnecessary stress to him.

And Loyaly, your store sounds like a great store.(Although I have to say, you're not there to supervise all the hands washing and employees dont always follow the rules) The stores around here are not as organized and careful and majority of people working there are teenagers. Most of them love animals and to others its just a job, but love is not enough to properly care for them nor does it mean they have all the knowledge they need.
If you are curious as to what I have reported:
Sick/injured rodents and snakes for sale(my understanding is, as I was told by investigators, they're supposed to be removed and isolated in the back for the vet to check/treat them)
Cages with empty water bottles/bedding soaked for DAYS
Rats/mice picked up by tails(one those instances ended up in degloving )
I've pointed out pet rodents of different sex being kept together(and for sale, with some already pregnant) with nothing being done about it
Inhumane traps used for catching escaped mice/rats
Selling snake food(prekilled) that was left out of the fridge for 2 days
Bird that lost an eye, I'm assuming in a fight with another bird, still kept in the cage with the others(with no sign of medical care)

And I can't tell you home many times I've heard EMPLOYEES and MANAGERS say to customers that sexing rats and mice is 'difficult' and 'can't be guaranteed for sure'....I mean, come on! Male rats and mice have big testicles!! lol That right there makes me question EVERYTHING that's being done in those stores and qualifications of people taking care of animals.

I actually don't shop anymore at any big chain stores that sell live animals(my parents do though grrr). I only shop at those that sell strictly food/supplies or my local family owned store (where I got my Iago 12 years ago)

PS. I added a couple of pictures of my Iago to my gallery, if you want to check out my little guy.

I can't say I like Petco very much. The cage sizes are plenty big, but they only have 1 perch in most cages and hang toys up high where the birds cannot possibly reach them. They do at least keep the cages clean, feed them reasonably well, and give them all names. The budgies are kept in an aviary type cage with lots of perches and toys. But really, even the best Petcos, and most other pet stores, get their birds from large-scale breeders, who often will pull and incubate eggs so the babies never get any contact with their parents, which can mean poorer health, and babies are clipped without being allowed to fledge, which can cause behavior problems later. If I wanted to get another bird, I would find a breeder that leaves babies with thier parents for at least the first few weeks and who lets them fledge well, ect.

Karen
Chico (conure) and Pippin (budgie)
WI