My Simon isnt well

[simon'smom]

again, this time we went away for 5 days, and put him in the kennel/vet. we always use. I come back to pick him up, and the vet said- He was lame on Sat, so we have him some pain meds, and he was licking his paws a lot. His skin was red between the toes, too. So after a whopper of a vet bill- i have him taking meds 2x a day- antibiotics and pain meds. Now he is throwing up every meal. Not good for any dog, especially a 170 lb saint bernard.
(btw, he lost weight it seems.)
He was fine when we brought him- but we recall a few other times he came home from there, not quite like he used to be.
I am kinda pissed about this- and more importantly worried about Simon. Any suggestions? thanks- aj