We have one dog and she is home alone all day, although at the start it wasn't like that, as I could go home everyday for lunch. Things change and your circumstances may not always stay as you want them to. In this day and age, if I was to wait until one of us was home all day or working part time, I would be 65 before I could get a dog. Its not an ideal situation and I find myself rushing home as early as possible to be with her, I no longer browse the shops after work and if I meet friends, it is always for lunch and not in the evening. We don't go places at weekends unless we can leave her with the in laws or my parents and that is the reality of having a dog.
While I would love to get another dog to keep her company, himself has put the foot down and said one is enough. I firmly believe (and this is not justifying it to myself) that a dog on its own during the day is far better than a dog stuck in a dogs home for months before the inevitable happens. However, as a previous poster said, a dog does need mental stimulation and there are lots of things you can do to stave off boredom for the dog, interactive toys, kongs, even simple things like a bit of rope tied to a tree with a ball or plastic thing attached will keep them amused for a long time. You will get a lot of advice on irishdogs.ie, but like here, it will be conflicting. Many shelters will not home animals where you are out all day, which precludes a lot of loving owners from providing good homes for needy dogs. Don't forget your local pound, which is where I got mine...or she got me...depending on your outlook. Be very careful where you buy a pure bred pup, many of them are puppy breeders and highly bred dogs tend to be more prone to inherited/breed specific diseases. Labradoodles can suffer from epilepsy, labradors from hip dysplasia (sp) etc. You can't beat a mongrel for sturdiness!