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'm guessing you've never lived on your own and owned a pet.
Getting a cat or a dog is a long term commitment and it CAN affect your future prospects. I have a cat, and have had to turn down consulting jobs that would require me to be out of town for long periods of time. I went with a cat because I can leave her alone for a week (i've gone up to 7 days) alone with plenty of food and water to carry her. But you can't do this with a dog.
As for dog-walking services, personally I wouldn't trust anybody whom I didn't know pretty damn well to have access to my home. Call me paranoid.
Plus you have to plan to give that animal care and attention for the rest of it's life. There's a lot of considerations that should go into making that decision. That is not a trivial decision to make.