Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your wee one’s situation, and wanted to help.
Again I do apologize that my colleagues could not aid you sooner, but wanted to touch base with you about Billy Bob.
I must say I am very concerned about your wee bird, especially if he is showing signs of breathing issues. This breathing changes and tail bobbing suggest that he may not be able to exchange oxygen as well as he normally has been able to do. So, as his breathing is abnormal, it is prudent to have him seen as soon as possible. Because if he is struggling to breath, then this is a red flag of urgency and he may need a local vet to start oxygen to stabilize him while addressing what is causing this.
As I am sure you can appreciate just like people, birds can suffer breathing difficulties for a variety reasons. Specifically, a respiratory infection in this species can be caused by bacteria, fungus, parasitic, nutritional (ie Vitamin A deficiency), and viral agents. Furthermore, we can see breathing troubles secondary to heart problems and even masses or tumors within the abdomen. And while you haven't noted how sudden the onset of the respiratory distress has been, if it has been sudden you do need to make sure there are no chemicals/fumes/smoke that could be to blame.
The problem I am sure you will appreciate with birds to that they do a very good job of covering up when they are sick. This is because as a prey species, attention to your illness will make you a target for predation. So, if we are even seeing him like this then we need to pay attention and address this aggressively before it can become an even more serious issue. Too often we are the last to know when our birds are sick. And too often we only see signs of struggling when their condition is just too advanced for them to hide any longer. Therefore, bird instinct puts us human owners at a disadvantage for catching things early, and makes addressing the signs we are seeing now even more important.
Therefore, it would be prudent to get a local vet involved at this stage to rule out those differentials and initiate appropriate treatment. They can examine Billy Bob, listen to his chest and determine if there is a respiratory infection (and if so, to what extent). Depending on the vet’s exam findings, they will be able to advise you on which causative agent might be present, and guide you on diagnostics and treatment steps to get him well. Now I see that you are struggling to find a local avian vet, so I would note that you can check the RCVS Register (http://findavet.rcvs.org.uk/find-a-vet/) to find one. Also many of the UK vet schools (ie Edinburgh, Bristol, RVC, etc.) will either have an exotics vet on site or will have ties to one that they can refer you to (ie. Glasgow). As well, you can check here http://aemv.org/index.php/members/vet-locator
While you are sorting out veterinary care, if he looks chilled and fluffed up, then do make sure you are keeping him warm. Other measures would be to cover three sides of the cage to keep heat in or consider moving him to a little hospital cage (one level with a soft substrate floor). You can use a heat lamp, or a heating pad under half his cage (do not put it in the cage) but do monitor closely.
Overall, your lad's breathing is a serious concern here that we don't want to leave to linger. If he is struggling, then we do have to consider having a local vet involved urgently to get help and address this respiratory issue. This will give you the best chance of helping address this and getting him back to breathing comfortably.
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