Birds need a great deal of food daily to survive. Their metabolism is very high; therefore, they must intake regular amounts of food. If you notice that your bird is not eating or if you can feel your bird's keel bone (the bone between its breast that runs vertically from its upper chest to it stomach area) very easily, take your bird to your veterinarian as soon as possible. Loss of appetite can be a symptom of parasites (especially Trichomonas), psittacine dilatation syndrome (PDS, also known as macaw wasting disease), a fungal infection or any number of other illnesses.