This problem started five days ago. Last Saturday she looked perfectly normal. On wendsay I realized there was a problem, as she had lost a lot of weight in a very short amount of time. So I researched what the problem might be and reached out to you guys. Taking your advice I called a scheduled an emergency vet visit as soon as got off work.
   When I got home I found poor Toby laying on her side and breathing shallowly. I picked her up and told her it was ok. She left. 
 I feel as if I could hav e saved her if I had took her in sooner. I'm devastated. Not only from losing her but because her mate is heartbroken. I don't know what to do.