I have a 5 month old golden retriever who started getting sick 1 month ago. At first I thought that she had injured her back end as she seemed to favor it. She was week and paced a lot. Her appetite however was good, except that she would occasionally not eat a meal. She drank plenty and her bowel movements were fine. The vet ran blood work which showed elevated liver enzymes and increase in white blood cells. She was given a dose of antibiotics. Since then she has gained some weight and seemed to be doing better. Recently she has begun to look thin again and she often will pace all night have excessive drooling at which time she won't eat. Her bowel movements are usually normal but on occassion she does have soft stool with thick mucous. When she is feeling "better" her energy level does not hold for a puppy. She tiers quickly and her front paws shake. Can you shed any light on what might be going on?

Optional Information:
Age: <1; Female; Breed: Golden retriever

Already Tried:
Soft can food only. Vet gave one round of antibiotic Fecal exam neg.