Greetings, I am Dr. Pat. I have worked with birds for many years. I will do my best to help you. I am sorry no other expert has taken your question. We all come online at different times, I have just logged in and saw that you have not been answered. I hope I can still be of assistance.Firstly I would worry that something is very wrong and he is either irritable or in pain. ANY change in behavior is worth a visit to a vet with geriatric bird experience. He certainly should have a range of diagnostic tests run. Has there been major change: hosuse renovations, new people, pets, guests, etc? New diet? Any accidents or mishaps? Is therre anything that you do that seems to trigger this behavior? Has your life changed or are you having any problems he may be picking up on?In Amazons the most likely cause of acute biting is spike in reproductive hormones. If this has not happened in the past, I would really worry that something unusual is causing excessive hormmone production--such as reproductive tumor, nutritional upset, metabolic disease, sleep deprivation or a combination of all the above. And these need to be sorted out by a series of tests.If this were my patient, and money no object, I would start with complete fecal analysis and direct smear, stained with Sedi-stain and unstained for multiple parasites, fungi, spirals; direct smear stained with Sedi-stain and unstained of the oral cavity; bacterial culture and sensitivity of the feces and choana. Depending on the case I might do a fungal culture. Routine blood work is necessary to rule out other issues. There are MANY DNA/RNA tests for bird diseases. Ultrasound would be my first choice, rather than radiographs, to check for reproductive tumor/abdominal organ health.To help moderate the aggression, he needs:1)excellent diet (see below for guidelines)2) health check3) 14 hours DARK, QUIET UNINTERRUPTED SLEEP AT NIGHT (no TV, people, lights on, nocturnal disturbance by people, pets, rodents, insects, noises)4) diversions, toys, excersize, outdoor timeEven if his entire lifestyle changes and there is not any disease, it will take a good month for things to calm down, so number5) patience abnd understanding.I know it is expensive, but you may not have many home options, because the first thing you need a vet for is to find out what is going on. Treatment is only as good as the diagnosis. If you call around, you may find a vet to work within your means. I really must stress that you need a bird-experienced person, and not just a vet who advertises that they care for birds. You need to take your bird to see an avian-experienced veterinarian ASAP for complete examination, diagnosis and appropriate treatment.
http://www.theparrotsocietyuk.org/index.php/Avian_Vets/28 http://www.avianveterinaryservices.co.uk/http://www.birdvet.co.uk/ http://alanjonesbirdvet.yolasite.com http://www.cjhall-vets.co.uk/index.asp www.marknelsonvet.co.ukwww.arkpetsonline.co.uk www.riversideanimalcentre.orgOnline you can check to see if this https://companionparrotonline.com/beak_book_detail.html is available; it has some practical solutions to common behavioral problems.He needs something to do with his mind. You can read children's books to him, point out the pictures, show him garden catalogs, teach him to count, anything to make him educated. Talk to him like an 8 year old kid. If he doesn't want to step up, explain that he needs to cooperate. NO DRAMA. walk away if he doesn't. Then come back and ask if he wants to step up, again. Use the same command and be consistent, not afraid, gently assertive, and NO DRAMA. Did I mention NO DRAMA?Here are a few suggestions that I give everyone: important!The following guidelines help with basic issues such as nutrition, obesity, good immune status. Surprising how the following can make a bird healthy, and how infrequently birds are ill if they are on the following regimen. No amount of medicine is going to work if the birds' basic needs are not met.