very sick lab, no ideas for her

Question
about 2 weeks ago i noticed my 6yr old female lab (then 68lbs.) had started licking her front paws, to the point of abcess. she has done this before and it then was due to the toes being torn between and causing irritation. our previous vet told us how to care for that condition, and we started soaking in warm water, or with hot towels to drain off the infection. I think it has gotten the best of her to this point, today is monday and this past friday we saw the family vet. he looked at the paws and prescribed an antibiotic along with benedyrl to relax her to claim her licking and chewing. That was friday, she now is continually vomiting up her liquids, keeps food down, but the liquids just gush out when she walks, gets off the couch, ect... No diareaha, just vomiting, she's lost about 8lbs now and I'm starting to worry even more, how serious of an issue is this or could it be, I would like to know the worst so I can be thrilled when it's nothing at all. She in the house most of the day, and lives in a fenced yard. We have a total of 4 dogs, the rest of them are all in perfect health....Could it be heartworm, pancreatis, what?????? I do have another vet visit tomorrow @ 3:00, I would just like to have other info available for my peace of mind,

Answer
I would be concerned that she is having a reaction to the antibiotics.  If she is vomiting that much, I would recommend that she be hospitalized on IV Fluids.  Additionally, blood tests should be taken to check kidney and liver function as well as screen for pancreatitis.  Abdominal x-rays may also be of use to check liver size, rule out foreign body or obstruction as well as evaluate the spleen, bladder, kidneys and bowels.

Until you get to the vet, withhold food and water...often times a 24 hour fast will help settle the GI tract.