However, it's important to note that this phrase is highly offensive and should be avoided.
Here's why:
* "Schweinhund" (pig dog) is a deeply insulting term used to refer to someone considered contemptible, cowardly, or treacherous.
* "Nein" (no) adds emphasis to the insult.
It's similar to calling someone a "dirty dog" in English, but much more severe and carries strong historical connotations of wartime propaganda.
If you're learning German, be very careful about using this phrase. It's not something you would ever say in polite conversation.