I love my cats beyond words, and I wouldn't trade them for anything, but I never imagined that they would be a life-time commitment. Beyond vet bills (if you're getting a puppy or kitten, look into insurance), consider your travel wishes/plans. If you want to get up and go to a week-end gathering, can you take the dog? will the dog travel well in the car? do you need to find somebody to take care of the dog if you leave it home? could you leave the dog home (or board it somewhere) if you had to be gone for 2 or 3 weeks?

Good luck,
Maryanne