Its your yard fenced? I personally, if it were my cat regardless of the situation, if he/she is going to be outside I would be there with them, maybe you can even put on a harness and leash while you are out there (if they have a tendency to take off) One of my uncles has a few cats, and they all learned from babies to be out in the yard playing but never to leave.
Now, I would probably try talking to Buddy's owner about the situation and let them know that if they don't fix this that unfortunately you will have to report the dog, its not safe for him to be running around, not just for other people but his own safety. If he is going to be left outside there should be a fence.
Also, my dad recently told me that pit bulls were sighted around his friend's pie shop. And we all know about the bloodthirsty reputation of those dogs! And those dogs already killed one cat. I don't want them to kill another, which leads me to my problem.
Definitely, if the dogs are on the loose, I would report them yes, so that they can be taken to a safe place. Now, I wouldn't judge them because of their "reputation" they are actually great loving dogs that many times fall in the hands of the wrong owners.
Good luck, and hopefully you don't have to drive to the mail box any more