I'm so very sorry for your loss and what you have gone through, but please do not think that this is a normal situation. For a parrot to die at only 2 years old after being ill for a year is not the norm, so please don't just write-off getting another bird. It sounds like you not only loved your bird very much, but that he brought you a lot of joy, as they typically do. This was not your fault, and this is not what is going to happen again...
If I can ask you a few questions about your bird's history that might solve some mysteries here and not only bring you some closure and peace, but also make you understand why this happened and how to avoid it from every happening again...
Where did you get your bird? From a shop or a private breeder? And where do you live, where is the breeder from? Was he a hand-raised Alexandrine, or a non-tame, parent-raised bird? How old was he when you brought him home? Was he completely weaned onto solid food when you brought him home, or did you still have to give him forumula feedings? What do you know about his breeder, are they know as a reputable breeder? Do they breed a bunch of different birds, or just the Alexandrines? Was your bird's breeder the same breeder who was giving you advice about his health issues? Was his breeder the same breeder who suggested you bring home another baby bird for him?
Because your bird was sick for much of the time that you had him, and based on the symptoms, it sounds very much to me like your bird unfortunately probably came from a shady breeder who only wanted to make money and who doesn't care much about their birds, especially if his breeder is the same breeder who was giving you the advice you mentioned about his health issues, and especially if his breeder is the breeder who suggested that you bring home another baby bird for your sick bird, and was the breeder who sold the moustache baby to you. These are all indications that this breeder only wants to make money, and sadly knew that your baby was sick or had health issues all along, probably when you brought him home...And ANY BREEDER OF BIRDS KNOWS DAMN WELL THAT YOU NEVER, EVER BRING HOME A SECOND BABY BIRD AS A SOLUTION TO SOLVING ANY ISSUE WITH A CURRENT BIRD, LEAST OF ALL A HEALTH ISSUE WITH THE SYMPTOMS YOUR BIRD HAD...That breeder just simply wanted to sell you another baby, as any and all parrot breeders know that the chances of a current 2 year old accepting a new baby into their home are slim to none, and that this is never a good idea.
I don't at all believe that your bird was regurgitating, as when they regurgitate the actions and movements they make as well as what comes out are completely different than when they vomit from a health issue...When they are regurgitating they head-bob, chirp and sing happily and make noises like they are trying to "court" you. And what comes up when they regurgitate looks nothing at all like vomit does. When they regurgitate they bring up very small, usually solid white pieces of food with no liquid at all. This is them trying to feed you or whoever they are bonded to, and they make that head-bobbing and neck motion in order to simply bring up only little bits of solids from their crops without any liquid, and typically the bits of solids they bring up are all-white in color and very small bits. In complete contrast, when they vomit it's very much like what happens when we vomit. They are not happy, they make no happy, chirping noises, they don't head-bob to bring up food, they actually heave and vomit-up EVERYTHING that is in their crop at the time, and sometimes what has passed out of their crop and into their stomach, and it's typically watery and more like what you would think vomit would look like. Regurgitation looks nothing like vomit.
The other indication that he was actually vomiting rather than regurgitating is what you described his feces looked like, being very watery with bits of green solids floating in it, that combined with the vomiting, along with the plucking and his feather condition tell me that your bird had a widespread infection throughout his entire gastrointestinal tract, and that he had it for quite a while. And if he was actually over-eating, it was most likely due to the fact that the infection that he had was causing his stomach to not feel full...
And I'm sorry to say, but whatever vet you went to does not at all sound like an Avian Vet to me...were they a Certified Avian Vet? I'm not at all blaming you here, this is in no way your fault, you have to take him to the vet you had near you, but there were a lot of red-flags to me with your vet visit...First of all they told you he was regurgitating, but it sounds to me like what your bird was doing had nothing at all to do with regurgitation, and this is reinforced not only by the fact that he died from the infection he had (he wouldn't have been regurgitating if he was as sick as he was), but the watery stools should have been an indication to the vet that it wasn't regurgitation but rather vomiting...And the biggest red-flag of all was the fact that the vet did a fecal swab and found budding yeast, and prescribed an antifungal medication, all of which makes sense, BUT THEY ALSO PRESCRIBED AN ANTIBIOTIC ALONG WITH THE ANTIFUNGAL...WHY? This is a HUGE no-no. First of all, why did they prescribe an antibiotic, which only treats bacterial infections, when the fecal culture only showed a fungal infection and no bacterial infection? They didn't do any other cultures or blood work did they? You didn't mention any other cultures they took or any test results they got back that indicated a Bacterial infections, so THEY SHOULD HAVE NEVER, EVER, EVER PUT YOUR BIRD ON AN ANTIBIOTIC!!! I hate to tell you this, but this could very likely be the reason that your bird passed away so quickly AFTER YOU STARTED HIM ON BOTH MEDICATIONS...THAT'S NOT A COINCIDENCE...
Here's what likely happened: I believe that your bird had been suffering from a widespread gastrointestinal fungal (yeast) infection for quite some time. This would explain all of his symptoms, the vomiting, the watery stools, and GI yeast/fungal infections are a very common cause of unhealthy plumage/feathers and feather plucking. So the vet was right to do the fecal culture, and when he found budding yeast in the fecal culture, he should have put your bird on a prescription antifungal, like micozanole, either orally or by injection, and also put your bird on a daily Probiotic supplement that had added digestive enzymes, and also suggested that you add a teaspoon of apple cider vinegar to his water daily. That's it, that's all he should have done, all he should have prescribed...But instead, the vet suggested that you do blood work, which would be fine and was a good idea, as a normal, routine blood panel could have shown an elevated white blood cell count, indicating a bacterial infection, OR if his blood work would have come back normal then he would have known there was no bacterial infection and it was just the fungal/yeast infection...BUT instead, the vet made the poor decision to also prescribe an antibiotic in addition to the antifungal, EVEN THOUGH HE HAD NO INDICATION THAT YOUR BIRD HAD ANY BACTERIAL INFECTION...THIS IS USUALLY DONE BY VETS WHO KNOW VERY LITTLE ABOUT BIRDS "JUST IN CASE", AND IT ENDS IN HEARTBREAK...
I don't know how much you know about gastrointestinal health, but in-short, birds, people, reptiles, etc., we all have a lot of normal, healthy bacteria living all throughout our gastrointestinal tracts that cause us no issues, we don't get sick from these bacteria, but they are rather very beneficial to us, to birds, etc. BECAUSE THEY KEEP FUNGI, SPECIFICALLY YEAST, FROM GROWING THROUGHOUT THE GI TRACT! So it should make sense that when you take an antibiotic, especially a broad-spectrum antibiotic that kills lots of different kinds of bacteria, THE ANTIBIOTIC KILLS OFF ALL OF THE HEALTHY, NORMAL BACTERIA THROUGHOUT THE BIRD'S GASTROINTESTINAL TRACT, AND THIS ALLOWS FUNGI, SPECIFICALLY YEAST, TO GROW OUT OF CONTROL ALL THROUGH THE GI TRACT... for example Baytril (Enrofloaxcin) is a common example of a broad-spectrum antibiotic that is often prescribed to birds that can do this...
SECOND PART BELOW!!!
She could have ingested the rope fibers and got a crop impaction which could have caused issues digesting food and caused the regurgitation and weight loss.
