http://www.nononsenseselfdefense.com/
First off, think like a criminal for a moment or three. What do you have that he (or she) would want? Then harden that portion of your life. Know that a professional will defeat whatever you have set up if it's worth his while.
Renter's Insurance for personal property? (I only mention this as some things are NOT worth dying or killing over)
Dog. Good. Early alarm system in place AND it has teeth and loyalty.
Others have covered access points.
Knowing your neighbors has also been discussed.
Safe Room. Cell phone, flashlight, firearm. LOCKED DOOR. Is there an escape route? (probably not from a 3rd floor apt) Nothing wrong in running away with Pup in tow (if you can get him/her off the BG's face). Cover? (something to hide behind which should shield you from incoming, yet allow you to peer around/over and return fire if need be)
Mindset. Are you ready to release the animal inside you? Have you trained that animal? Re-read MacYoung's cover page and ALL of his links (in red). What's he say... "Personal safety is not about your ability to fight"?
But let's say, for argument sake, you find you gotta fight...
I don't know how "weapon-available" you are. Or even IF you are willing to go there. Kitchen knives (ick up close) you've probably got. Got a hammer? (also ick, also up close) Baseball bat? (ick with more distance) O.C. Pepper Spray (point it the right way please and watch out for friendly fire coming back atcha)? (not quite so ick, not quite so reliable either)
Finally... a firearm. Any firearm is better than no firearm but some are better than others for what you (hope you never) need. Training req'd. (ick, but at a distance... loud, too) The sight of you with a firearm pointed at an intruder might make him rethink his desire to intrude on your life/personal space. Maybe. Hopefully. Even if you can't tell he's armed, he's violated your abode and deserves something for his efforts, because if you don't stop him now, he'll do it again to some other poor victim, over and over. Til he's caught.
You feared for your life. He got past your dog.
sigh.
Know your local laws. Texas is one thing. NYC another. (I add that cause other's lurking might not live in TX like you)
After you get done doing whatever you do, call the police if you haven't already.
Read Pax's Cornered Cat.
http://www.corneredcat.com/