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.THIS IS A VETERINARY EMERGENCY AND HE NEEDS TO SEE A BIRD-EXPERIENCED VET IMMEDIATELY.
If I was his vet, I would start oxygen immediately, have him in ICU. I would start him on antibiotic injections, fungal treatment, anxiety control and possibly other medications until test results came in. I would do an ultrasound scan of cardiac and abdominal regions.
He may have pneumonia, fungal infection, tracheal blockage, toxicity or any other number of issues. Amazons are prone to obesity and heart problems. The issues need to be sorted out so he can have targeted treatment.
Without a diagnosis, I cannot recommend any particular course of treatment, except good nursing care at home.
If you feel comfortable with it, examine the bird thoroughly, using gentle restraint via washcloth or hand towel: do not restrict the chest or hold around the body. Check the eyes, nostrils, mouth and beak if possible, having a good look in there for mucus, redness, masses or anything else unusual. Palpate the tummy for pain, fluid, lumps or anything else (eggs, if female or unknown). Check all the joints for swelling, pain, and mobility. The feathers should be parted to view the skin, muscles and skeleton below; this can be done using a q-tip with isopropyl alcohol or KY gel. Look for bruising, lacerations, injured feathers.
Your job is to keep the bird warm, safe, quiet, and confined; and to provide adequate hydration and calories.
Move the bird to a box or carrier with soft towels in the bottom, no perch, and food and water in low bowls that can be reached easily. Put the whole thing on a heating pad on low or medium. Check it frequently, no overheating allowed! Keep the unit partially covered, warm and quiet. White paper towels or white cloth towels will show the true color of the droppings. Small animal/reptile boxes are great for this purpose.
The bird, bowls and unit must be kept very clean.
Here are some helpful links:
Do not try to force food or water. Pedialyte or electrolyte replacer can help but many birds do not like them; when in doubt, plain warm water is best. They can hydrate from oral fluids almost as quickly as IV if the GI is functioning properly. You can offer warm cooked rice, pancakes, cornbread, grapes, melon, greens in addition to normal food.
Pet/feed store medications and home remedies are harmful, ineffective, immuno-suppressive, and make them much worse and may interfere with the veterinarian's diagnosis and treatment. Do not use them. Homeopathy and natureopathic techniques do not work in avians and can actually be very dangerous.
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. Check
for members of AAV in your area or call your regular vet and see who they recommend; ask if they really have worked with birds a lot. Unfortunately, this list does not rate competency or experience, but is only a starting place; the vets at least take the avian medicine journal and hopefully see a bird or two a year. The best referrals are word-of-mouth, so check with several non-bird vets, the humane society, parrot rescue groups, bird clubs, etc. for their input. As you might guess there may be controversy and varying opinions even with this. Even board-certified avian specialists may not have a lot of practical bird experience. Unfortunately there are few resources available to refer you to really good, clinically-experienced bird vets.
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 is often more informative than radiographs and does not require anesthesia (ask your vet about this option). Generally I start them out on medications as indicated by the tests.
Your bird may need injectable fluids, calcium, antibiotics and many other medications. Act quickly and good luck.