Perhaps the fact that none of Tess's "clothes" fit her very well should tip me off to the fact that Brittanies are not made to wear clothes!!!!! Take the pictures above. Cheap $10 Walmart dog jacket. Why would I even bother?
In addition to this jacket, she also has several other items that don't seem to serve a purpose: a ruff wear reflective jacket, and, if it was on a horse, what I would call a "slinky".
These items do very little for the dog and a lot for anyone that might see her.
Tess is now reliable off leash!!!!!! I live in a semi-rural area where we now bike, ride, run etc. and she can be around me off leash. For people that might be meeting us on the "trail" (it's not a trail, it's not a road....it's something undefinable that is still OK to bike on) or her might see her running around before they see me, clothing signals that she belongs to someone, that she's likely not out there by herself, and makes her seem more friendly and approachable for someone that might be nervous. Yes, I call her to my side when ever we see anyone else or animals, but the clothes seem to be a nice social signal --> A dog is perceived as less as a threat and more in the "cuteness" range and more well attached to a well meaning human than one with out.
Another reason for clothes is visibility during town activities. Tess is already very visible because of her color, but adding another bright color or something with reflective striping is an additional safety when she's biking with me on the road, or we are going for a nice on leash walk. I feel like I'm more visible crossing a sidewalk in a busy intersection with her in a bright jacket, than by myself.
The third reason for clothing and the slinky is for mud control......There's something about the way Tess moves that soaks her belly with water and whatever else is on the road when we bike into school. On particularly wet days, I'll ask her to wear the slinky so that she can walk into the vet school semi clean and dry, since it IS a public place and it wouldn't be nice for the other students and faculty to have to steer clear of mud patches put there by my dog. Another use for the slinky is when she DOES get to be filthy and muddy......after a bath I put in on the limit the amount of wet shaking.
If I'm being totally honest, Tess is not a huge fan of clothing (or any other kind of restraint for that matter). So when I do ask her to put something on, I try to make sure it has a functional purpose (backpack) or a safety purpose. The slinky is boderline --> that's for the comfort of humans strictly --> but the upside is it allows her to come to school with me on icky days, so she will make the exception for me!
Do you dress up your dog? Does your dog like it? Do you have certain criteria that need to be met before they get to be non-naked?