My mums old lurcher once ate an entire tub of really cheap margarine she'd stolen off the kitchen side.
Which is disgusting in itself.
But she then threw it straight back up again in an ectoplasmic spray of yellow slimy grease, straight on Mums favourite rug.
Mum told dog off, dog then proceeds to leap the back gate and vanish for two days, finally found running behind a bus! 
That rug never got clean btw!
My dog, which funnily enough is also a lurcher (hmm...wonder what the connection is?
) is just truly disgusting.
The worst was finding a savaged pigeon in the woods, complete with entrails, feathers etc, must have been several days old
I could see what was going to happen before I got there, as I started to run frantically down the track shouting "No Ddog, NO!" she gave me one sly look and buried her head in it, literally chomping as much as she could before I got to her, she then threw herself in it, just before I got there.
She was covered in it, it was the most disgusting thing I have ever seen.
Until that night when she started vomiting feathers, bones and maggots, then spent the next two days shitting round the garden like a fire hose.
Took her to the vet, cursing her all the fucking way .
Bloody git.