I'll come clean as well. Before I found this forum I didn't know there was a difference between good and bad dog foods. I would often time feed Gizmo the Moist 'n Meaty. I think it was Moist 'n Meaty. If it wasn't that brand it was something close. It had a sheltie/collie on the front so Mom bought it.

My mom thought it was cute because we were feeding a sheltie something with a collie/sheltie on the front package.
As for the getting him to eat I don't know what would work. Smudge will eat anything (including pieces of paper off the floor, newspaper, Kleenex, paper towels, my sister's new shoes that she just got not two weeks ago, ect.). When we first brought Gizmo home he scared me, because he would only take a bite or two the entire day for the first couple of days. He finally came around. Gizmo was a much pickier eater than Smudge.
It does make me sick that he's so small. How tall is he? Is he the right weight for his very small height? Or is he really bony and you just can't tell it because of the fur? Speaking of which, that picture of his fur made me MAD.

Why would anybody do that to their dog?! Did they not see the damage it was causing? My sister had a bad problem with her hair once. I took her to see my hair guy (he's very good

) and he told her that her hair was so damaged that it would be better to just cut/really trim the damaged parts up. It took her hair a long time before she was able to stop using special shampoos and treatments for it. I hope you don't have to cut his pretty fur because somebody else couldn't use common sense.
I hope you get good news at the vet when you go back.