Yes! I mean look at how CUTE they are! I tried to give this answer to my Fiancé, but he wasn’t going for it… So I got to thinking, should they? They do have all that fur and what not. Well it turns out the folks over at www.petmd.com had a similar question. The way they see it is your dog may have fur, but not all dogs are adapted to winter conditions the same. Short/Thin haired and smaller breeds such as Chihuahuas, Grey Hounds and Terrier Breeds would benefit from some extra warmth on those cold nights. Beware however; larger breeds such as Siberian Huskies, St. Bernard and Malamute have been genetically adapted to winter conditions and would be very uncomfortable or overheat.
Now as far as for when it’s not winter I say go for it! As long as you are making sure to dress the animal appropriate for its weather situation a little fashion won’t hurt. My dog loves to wear shirts and dresses so much that she even drags them out of the dirty hamper! Have fun with your dog, it’s 2014 and everything has the right to look fabulous!