The picking up of poo would be teh thing to put me off most and then having to get the dog looked after if you go abroad although for a fee you can usually take them to kennels.
Just think though, every poo your dog does for the rest of its life, has to be scooped up by you! I didn't mind scrapingthe poo off my babies bums but dog poo is altogether something else!
To be honest I would wait until ds was a bit older before getting a dog especially of you are going to get a puppy or get a rescue one which may have unpredictable behaviour.
We have a dog, it belonged to dp before we were together and it has taken me about three to four years to accept having a dog and ours is a nicer dog than most I have met.
We have a lifestyle that suits a dog, we do lots of camping and we go fell walking at the weekend but even then I ahve times when I regret having him - for example our garden is wrecked, if we go abroad or to a hotel we have to rely on people to look after him and as a springer he needs about 2 hours a day which means me walking a dog at 5 in the morning.