Check with the city. Where I live if I find roaming dogs and call the city, they'll send over a trap and catch it, haul it to the pound. I really wish I HAD done this last year because I was 'nice' and let my neighbor's dog run. It eventually squeezed under my fence and killed most of my roosters. (Thanks goodness the hens were still penned!)
The next day we actually caught the dog in the act (not literally, my dh just saw it in the pen chasing the rooster who snuck out again and he chased it out.) he called the sheriff's office, who had the pound haul it off. They also did a report because the dog killed my animals--which means the dog could be released from the pound--but only if it never came back in the city limits. If I really wanted to be nasty I could have insisted they pay for my birds too (and if they ever get another dog they allow to roam, we will go over and in no uncertain terms explain the consequences if their dog bothers my animals, and it won't be cheap!). I decided since they lost their dog (that they totally ignored) anyway, I would let it go. They haven't gotten another one. They are really serious about animals roaming here, and especially on ones that kill livestock.
I'd call the city and see what the actual ordinances/rules are and if necessary, just have someone pop by and explain about leash laws to these people.
I sometimes cringe when I hear my geese going at it in the middle of the night, and I know guineas aren't as noisy. I have my geese for protection, too! You have a right to your birds too, and if they stay on your property, you're being a more considerate neighbor than they are!