Azygus said (in post I quoted)
An oral antibiotic would be wise if you are in possession of one or order at the link I provide below. Here is my wound protocol:
1. Treat for shock as the number one step. Give warm Gatoraid or mix a half teaspoon of sugar into a fourth of a cup of warm water...
first treat for shock
this post has the protocol
https://www.backyardchickens.com/threads/found-a-gaping-wound-some-advice-would-be-appreciated-nsfw-pic-in-post.1568450/
I know you have a duck and the post is about a chicken but no matter. Azygous protocol is very good