From the Dogster about page:

“Why Dogster? We are dog freaks and computer geeks, unafraid to admit that when we see a dog, any dog, our heads turn and we howl with delight. Who wants a cookie? Who does? Well, we do and we think it’s about time there is a social networking application that is truly for the dogs. We hope you do too! All the dogs in the house say Wooooof! … Wooooooooof!”

Bah! Social networking is for the dogs ;-)