Whenever a new bird enters a flock, there is a chance that it can be carrying a disease latently that even quarantine will not reveal. Polyoma is not the only worry. Intestinal parasites, red mites, viruses, harmless feather lice, etc., can sneak in undetected. Psitticosis can be carried by a symptomless bird. Having a bird in an outside flight can raise the chances of diseases caught from wild birds.
Quarantine is vital, and many problems will be revealed as the stress of a new environment will bring the new bird’s immune system lower and allow hidden problems to surface, but not always. When we get a new bird we automatically treat it (symptoms or not) for feather lice, red mites and internal parasites. (Ivermectin is an excellent med for this).
We found this out the hard way when one of our new birds apparently (even after quarantine) spread a virus through our aviary. It seemed to not bother the adults much, but killed several babies. We had to stop breeding immediately, and dosing with antibiotics was tedious. It took over 2 months to run its course. During that time, even after we had thought it was gone it would suddenly pop up again. We wouldn’t sell any babies from that set (though most babies were immediately separated and not affected that we know of, that was our choice as conscientious breeders), and by the time the virus had run its course, most were too old to sell as babies.
The whole thing was so discouraging that I really thought about quitting raising budgies. But we stuck it out and learned our lessons. We now treat all new birds (and introduce a lot less of them). If you need to add several new birds, buy them all from 1 source to avoid inheriting everyone’s problems. Having a large population as we do (70 to 80) makes this info all the more vital. By ignoring any of this the consequences can be far reaching and devastating. But these reminders can help anyone who wants to add a new bird and protect their little loved ones.
Have a clean, disinfected cage ready and set up for your new budgie(s) before you bring them home. I recommend treating all new arrivals for parasites by using a mite/lice spray and an internal parasite treatment. Always after handling the quarantined budgie(s), wash hands with soap and water before handling your other budgies or touching their cages and equipment. Don’t use any equipment with your other budgies that has come into contact with the quarantined budgie(s), such as food dishes, unless they have been properly disinfected. It is best to keep the quarantined budgie(s) caged in a separate room from your other budgies. Quarantine should last one month. If after 30 days no signs of parasite infestation or illness have developed, the quarantined budgie(s) may be introduced into your budgie population.