I say put electric fence up too. Not just for that one particular dog- It might also help if yours ever gets out too. You still need a good chicken pen or coop though. Electric fencing is not too expensive if you are not trying to make it too upscale. We used to split boards for posts (stobs) The insulators and wire are not too high new and you might get lucky and advertise on Craig'slist or Freecycle and get a used fencer unit. This isn't a 100% answer but I know how it is to find money for a project. And if that dog acts aggressive toward you or your kids on you property- Shoot and ask questions later. Make sure you get a good powerful fencer, One that won't short out every time a piece of grass falls on it. Good luck and I hope you get everything together to get your chickens!!