A little less than a month ago, my budgie, Darwin started to act strange. He was sitting very low on his perch and being very tired. I took him to the emergency vet where he started struggling to breathe. He got lucky, and ended up being ok. He had to get antibiotics for about 10 days. He seemed much better by the end, but since he is not trained, he got scared by me having to grab him and give him his antibiotics twice a day.
Starting 4 days ago at around evening, he started panting for some reason. The panting only would last for about 30 seconds, sometimes longer, sometimes only for 5 seconds. He had his feathers close to his body as well. He is not panting as much, but today he ended up hitting something while flying around outside the cage, he tried to land on the perch, but instead he missed and landed on the ground. His claws got stuck on the carpet (I need to trim them) and I tried to help him but he flew onto the side of his cage, and stayed for about 1 or 2 minutes. Afterwards, he was panting heavily for about 15 minutes, and for another 15 minutes he was not really open mouth panting, but I could still see his chest expanding and contracting. He is fine by the way and he has stopped panting. These panting phases seem to come on occasionally when he gets scared or someone gets close to his cage.
During the days when he has been doing this behavior, he has been eating and drinking normally, He has been chirping, He does seem to keep his feathers close to himself quite a lot, but he still fluffs himself up. His posture has been fine, but I did notice that his tail has been pointing down a lot. I got a new perch for him recently, so it could be the wrong size for him and maybe that's why he's doing that. I'm not sure if he has been doing this thing with his tail before though. He still takes little beak swipes at his cage-mate when his cage-made gets in his space (don't worry this is normal and harmless behavior for them) He still likes to play with toys and wear his bell as a hat. He seems to have no problems moving around or flying I think.
I really hope nothing is seriously wrong because I can't afford another trip to the emergency vet.