The appearance of maggots can gross out even the most experienced veterinary professional. However, if caught in time, a maggot infestation is very treatable. Did you know in certain situations some Veterinary pros will use maggots to clean a wound? Really gross, I know, but they do an incredible job of clearing out infected tissue. Once you clean out the infestation ( washing the area with cat flea shampoo works great!) treat the wound as you normally would. Just be aware if you have maggots in one area you need to be especially vigilant to watch for other areas of possible infestation-under the wings. Remember, maggots like moist/humid/warm flesh to grow in. If you do treat the area with any type of cream/spray/washing make sure you dry the area completely. Your fleshy giant my enjoy a quick once over with a hair dryer after being treated. And since he is moribund be mindful of pressure sores that will develop on his chest. I know this situation is stressful for you, and this might not turn out the way you want, but always remember you gave this bird a chance. Something he didn't have until he met you.