I used to bring my dog to work whenever I could, even back when I worked in actual offices. As it turns out, it can be beneficial for those other than just the pet owner. Mental Floss has all kinds of reasons that you really ought to try bringing your dog or cat to the office every now and again.
Pets can reduce stress levels, help spruce up the office space, make people more social and make people take more breaks, which are really important to morale and concentration. If you're an employer, you might even suggest the idea to your empoyees -of course take any worker allergies into account first.