... I couldn't imagine going back to that. I missed having dogs when I didn't have one for practical reasons.
Deadly to your future success? Get a grip. It's a d**mn dog. If you want it, get one. If not, don't get one. You make the decision just like everyone else and stop acting like a law student by being so overly dramatic about relatively trivial things.
I would just keep in mind your job search plans for first semester 2L; if you have a puppy at home, you can't board her until she has all of her shots. This means unless you have someone willing to spend the night with him/her, you can't travel for interviews/callbacks.