We are a long way from making a decision on this yet, but the main thing that's holding us back from getting a puppy is we have a 13 year old cat.
He is generally in good health but has never been around dogs... he shoots back home through his cat flap when he hears one.
Would it be cruel and stressful for the cat at his stage of life to get a puppy? (He adapted well to the kids when he was younger! He is very gentle generally.)