Most bird diseases present with respiratory, neurological and digestive signs, trying to diagnose it via the internet is impossible, picking some random diseases you’ve heard bandied about isn’t a great strategy and could be detrimental. On the old House tv series everything was always lupus at first, except it never was. Poultry always have mareks or coccidia unless they are egg bound! Symptoms are very rarely diagnostic, a cough is pretty much a cough whether it is a tickle in the throat or Covid, each organ system only has certain ways to respond to insult and injury. Also, don’t idly pick diseases on state or federal regulatory lists for something far less serious and much more common, exotic Newcastle disease and AI often mean flock depopulation and people walking around in hazmat suits, not something to guess about for a sniffly bird every fortnight when it just could be mycoplasma. If you have birds dropping dead daily, then yes, it could be something serious and you should get professional help asap, not be polling the interwebs. Good husbandry and nutrition are your best treatment and prevention strategies for most everything, if you really need to know, send in a whole bird or three to your state diagnostic lab, but half the time it comes back inconclusive so keep that in mind, but it is way more helpful than googling it!
