Of all the pet portraits in this challenge I like this one the best. The color of the sofa works great to isolate the dog. The lighting is perfect for this shot as well. Doesn't seem put off too much by the camera. :D Good luck in the challenge.
edit to update. Well you got bumped by a cat portrait. (don't tell Gilly!). Still my favorite dog portrait of all the pet ones. :D
Funny, my dog won't even get on the couch for some reason. Even if I pick her up and put her on the couch she immediately gets off of it. Strange. Anyway, you've got a great photo here...I think top 10.