I have a 2 year old papillon that's been very active and healthy. Last Thursday, she started putting no weight on her right hind foot and cried when anything touched it. We took her to the vet, xrays didn't show any visible trauma, so the vet placed her on Rimadyl for a few days. She had the prescribed two doses Thursday, and by Friday she wasn't really limping anymore but she seemed more quiet than usual (not barking, walking not running, decreased appetite) so I didn't give her anymore Rimadyl. Friday night she was fevered, had abdominal swelling, very lethargic, weak. I called the 24 hr animal hospital and was told to monitor her overnight but that she should be fine by morning as it was over 24 hrs since the last dose of the med. About 5:00 am her fever broke, she drank a little water and ate a couple bites of food. The abdominal swelling also went down. We took her back to the vet Saturday morning and had bloodwork done to check liver and kidney function. The vet said everything looked good, don't give anymore Rimadyl, she should be fine in a couple of days, and gave her metoclopramide, famotidine, and a hydration injection. Sunday she seemed okay but she still had some weakness and decreased appetite. Monday afternoon, she suddenly started limping on her left front paw and shortly afterward began drooling, had tremors, and her head was lagging. We rushed her back to the vet where she was diagnosed with seizures, and the vet said the random limping was probably due to muscle cramps associated with seizures. While at the vet she had another seizure so they gave her an injection of valium and phenobarbital and started her on phb tabs twice a day. By Tuesday we noticed the abdominal swelling seemed to have started again. Today, she went back to the vet for a checkup, and she has gained almost 3 lbs since Thursday (from 10 to 12.11). She has now been placed on metronidazole, metoclopramide, gabapentin, and phenobarbital, and was given another hydration injection. Because of the abdominal swelling/weight gain she now resembles a pot-bellied pig, and she can no longer jump on the bed and has trouble maneuvering the stairs. Has anyone else been through something like this? What could cause a 3lb weight gain in a week? Her labs looked good, so the only thing I can think of is congestive heart failure. She's never had seizures before, is it from the Rimadyl? What king of neurological damage can we expect, if any? I don't feel like I'm getting answers from the vet, just more meds. Any thoughts?