Hope Hanna is starting to do better. Here are 2 of the links from when Ellie had her spay and had problems. Not saying thats what happened with your girl but just to read for informational value, never hurts to be over educated!!
http://www.sheltieforums.com/showthread.php?t=2144
http://www.sheltieforums.com/showthread.php?t=2306
If you do a search on Ellie on page 6 there is quite a few threads on the whole incident and surgeries.

http://www.sheltieforums.com/showthread.php?t=2144
http://www.sheltieforums.com/showthread.php?t=2306
If you do a search on Ellie on page 6 there is quite a few threads on the whole incident and surgeries.