My heart goes out to you. I went through the same problems with my old Rottweiler in 07. It's tough when they get older isn't it.
I can't remember exactly what information is in this thread but if you have any spare time you may want to look through it just in case there's something in there that may help. It's one of the threads I had going when my Rottweiller first started to display similar symptoms as your Sara.
If there's anything I can do for you please let me know, I'll do all I can.
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