Braise isnt eating

Since Thursday we have been keeping a close eye on our beautiful boy who is hardly eating and seems to be losing weight rather rapidly. He's still drinking plenty from his water bowl and his nose is still slightly damp.
He's a fussy eater usually, but I'm concerned now as he's showing no interest in his regular mash, biscuits, chicken or even smackos.
Today for example he has had two biscuit bones, and a piece of bacon, usually reserved for a sunday morning treat. Ive had to hand feed these to him, talking him through it and cuddling him at the same time while he stays on his bed.
The Hubby and kids came home from shopping today and Braise didnt look twice, or leave his bed and he barely lifted his head. Hes also shivering alot even though his bed has been in the sun all day. Safe to say Im worried.
He will visit our favourite vet tomorrow, so ill keep you posted. If there are any Dane owners with advice, it'd be greatly appreciated. Thanks x
*Weve got an a appointment at 3.30 this afternoon* (fingers crossed) here a a few more of his symptoms
~Pale gums, dry heaving,shedding hair alot, shivering,eyes seem extra gooey a bit yellow and slightly sunken, totally lethargic. But my baby boy wagged his tail a little when I wnet out to poor water in his mouth just then...x
~Blood taken... results to follow tomorrow...