Dr. Tully said since the fecal was clear, mainly he would check to see if the birds are in good body condition (good chest (pectoral) muscles, eating well, clean feathers around the nostrils, clean feathers around the vent, and having normal stool. Over and above are active and alert.
I will add that if there were other birds or animals in the same room, and conditions were crowded, it wouldn’t hurt to have a Chlamydia screening done, on at least one of the birds. And keep an eye on the droppings for any signs of parasites – these are rare in pet birds but in really poor conditions, are more likely to occur. The same goes for external parasites, but do not treat them for parasites unless they are diagnosed with them. Also watch for scaley face mites – they appear as coral-like growths around the eyes, beak and feet. These can appear in some parakeets when they are extremely stressed, but can be easily treated by the Vet.
As to behavior, if these birds are caged together, I would recommend either adding a fourth bird when all birds have been quarantined, or see which two tend to be bonded and put the third in a different cage. Generally when you keep an odd number of birds together, two will bond, even if they are all the same sex, and one bird gets left out, often getting bullied by the other two. You can leave them all together and just be aware of how they are interacting. But if you start to see two who always sit together and one by itself, it’s better to remove the odd bird. Bullying is not always overtly aggressive. Sometimes the odd bird will be followed constantly by one or both of the other birds, as a form of silent stalking and intimidation. It can be very stressful for the single bird. Always make sure there are as many food and water stations as birds when you keep multiple birds in one cage. Squabbles are normal, but if you see feathers being ripped out or blood being drawn, it’s time to split them up. Never provide a nest, nest box or anything they can get inside of or view as a nest unless you plan to breed them. Birds only use nests for their eggs and young – they do not sleep in nests the rest of the year. You would definitely have to remove the third bird if you end up with a male/female pair whether you set them up to breed or not.
Thank you for asking Lafeber,