If you live like I do in the country, there is no animal control, its the Sheriff's office that takes care of animal calls. There is no animal control in the small town where I am located, again the local city police of Sheriff does all animal control issues. So, you pretty much have to depend on yourself to take care of loose dogs.
Antifreeze will kill them, however it can take a few days or more to actually shut down their kidneys and this can be painful until they are comatose.. Bullets are faster and quicker. Put some hot wire around the bottom of the fence, you might find that will take care of the issues really quick, but your poor chickens might end up fried if they get too close.
As I suggested, try the rabies vaccination side of it. Check your state laws by calling the state veterinarian and find out the actual law for the state, I am sure, as in most states, they are mandatory. Then get ahold of the Sheriff and tell them you want to see current vaccination records FROM THE VET, not just made up shot records from the owners, for each and every dog. Since they are mean and run loose, there is a health risk for your safety and anyone who is going by that home. I imagine the Sheriff would be just as happy to get the population down before the dogs attack a human.