I'm going to tell my girlfriend she should get her dog euthanized
Why do you want your girlfriend's dog put down?
I've gotten bitten by my dog when he has gotten angry twice. He is also old and unattractive.
It's awful to try and tell your gf to do that to her dog. You should be more considerate of her feelings towards her pets.
What's wrong with my idea? I'm going to make an appointment tomorrow.
Have a long discussion about her dog with her first. Tell her how the dog has been treating you and you can work together to fix it's behavior. I am sure the dog means a lot to her and your concern for it would show her you care.