Not everyone can have a real, live, flesh-and-fur dog, both as a companion and as an extra pair of eyes keeping watch at home.
First either buy or make several small figurines of dogs. Get some red thread and an oil you associate with protection. Make a small collar out of the thread and tie around each of the dogs’ necks, and anoint with the oil. Then walk around your home, showing the dogs every door and window. As you do, check the locks to be sure they work well, and anoint the sills and thresholds with the same oil.
Then place a dog by each door and window. For each, say:
This window/door is now your charge. Keep it safe and guard it well, for this is your home as well as mine.
Fourth Quarter Moon in Libra