Calling All Shepherds and Sherherdesses!!!

If anyone can help solve the illness that has struck our sheep, Miniel, PLEASE HELP!
We finished six days of Penicillin treatment last Saturday, October 30th. After this regimen of Penicillin, we wanted to give Miniel's body a rest from the antibiotic. She was improving, but now has gone backwards in her progress. She has been lying down more in the past couple of days and it is very difficult for her to stand. When she is able to stand she is very shaky on her legs........her forelegs more than hind.  I started the Penicillin again last night and again this morning. We had been giving her 2 cc's Penicillin S.Q. and that is the dosage I continued. Our farmer friend, Tim, is coming over tonight with a different antibiotic and some worming medicine in case it is liver flukes that somehow managed to get in her central nervous system., although the vet didn't see any signs of worms. We continued the Probiotic every couple of days to ensure that her rumen is working. She continues to eat and drink appropriately passing formed stools.
I know there are shepherds and shepherdesses  in the blogosphere...............we would appreciate any and all suggestions, comments, etc.
Thank you so much!!!!!