Whilst doing a bit of research around this contentious topic, it became quickly apparent that there is no study or paper to find, which conclusively proves that feeding bread to waterfowl is the sole cause for the development of angel wing deformities. Despite this fact, most wildlife and waterfowl experts seem to agree that the overwhelming cause of angel wing is an unhealthily high protein and / or carbohydrate based diet. Unsurprisingly, it was not difficult to find plenty of advice and warnings suggesting not to feed bread to birds, and in particular not to waterfowl. However, with all the advice being provided, no scientific references were given, which would certainly help to clarify and understand the situation.
Caring for temporarily and permanently disabled birds is an important but also challenging aspect of bird rescue and rehabilitation. The specific needs of in particular temporarily disabled birds are often underestimated and sometimes even neglected. However, there is an increased risk of associated injuries affecting in particular birds with fractured wings or legs. Although the time span of this temporary disability or immobilisation seems very much limited, it is often long enough to cause considerable problems like joint stiffness or pressure sores. Naturally, this becomes more of a problem in long-term rehabilitation and for permanently disabled birds.