Dog?

We are a pet less family. Not because we don't like animals, just that our lives have never been conducive to having pets before. Well now that we are settled in a place we plan on being for awhile (we have moved 6 times in the last 7 years) and we own our home and it has a mostly fenced in backyard the question on whether or not to get a dog has come up several times.

My under 2 year-old is completely enamoured by dogs and "dog" was one of her first 4 words. The 5 year-old is still scared of dogs but she needs to get over it. My husband wants one. I am the hold out. I know it is the classic excuse but I just know that I will be the one in the end taking care of it. Additionally I don't see how it could be fair to the dog? When I go back to work (and that will happen) there are days in the winter when we feasibly leave the house around 7am and do not get back until after 9pm due to the running we have to do. I can't see this working.

So I am the bad guy at this point. Do any of you wise readers have any input on the situation? Do you have dogs/pets? How does it work?