The type of injury determines if it will heal. There are other issues that can cause neurological problems which prevent control of the neck muscles such as
ingestion of bacteriological toxins or other poisonous substances.

It will be difficult for the mother swan to care for the young as the male swan normally protects the entire family and provides time for the female to escape with the young. Now, that he is not around, she will have difficulty escaping and may have to stand and fight which if results in serious injury, could further jeopardize the young's we being. Furthermore, the female is not going to be able to rest, preen and bathe on her own without having to constantly keep an eye out for the cygnets.

Female swans usually, not always, but usually will take another mate if something happens to the original mate. This depends on the individual swan as well as when this might occur. She may or may not accept another mate until the cygnets are old enough to go out on their own. The Regal Swan