I don't give a ruff - A mean way to say you're not bothered and are probably going

A mean way to say you're not bothered and are probably going to say something rude.

I don't give a ruff you failed the test. I'm still going to eat my lunch.

I don't give a ruff you're crying. I'm watching my favorite show.

I don't give a ruff you said my dog was ugly. He's still my best friend.