Loki has a Casual Canine hoodie (ebay but I'm sure it orginaly came from
Pet Edge)
He also has a hoodie by this company:
http://www.allstardogs.com/ We bought it at a local boutique because you can't buy just one from their website, but I'm sure you might have a place near you.
I also am very pleased with his
Ruff Ruff & Meow shirt. He is a medium, even thought the size chart says he is a small. It's SO cute.
Also try
American Pup.