Several years ago I had a cat named shadow. She was a pure black female short hair that was my sweetheart.
I had a friend look after her during my big move to BC after my divorce. Long story short, my friend became really attached to her and asked if he could keep her.
Knowing that my life was till upside down and she was happy where she was, as much as I loved her I knew she would be better off where she was, and she was being well taken care of and spoiled rotten!

So One day I went into a pet store which I will often do just to visit the animals and get my animal fix for the day, when I noticed this little cat curled up in a cage who looked just like my "shadow" Now these animals at the store were actually brought in by the SPCA so they were all up for adoption. I asked if I could pet this little cat as it reminded me of the companionship I so much missed.
As I picked this cat up I noticed she had one difference in appearance compared to my shadow, she had a white patch on her throat. I pulled her close to me so she wouldnt be frightened and she immediatatley nuzzeled into my neck and started to purr very loudly. "CRAP" I said outloud to which the employee laughed and asked if she should begin the paperwork now... LOL
This cat was named "panther" and had been dumped off at the SPCA for the second time because she did not get along with other animals, especially other cats. I knew that this was her last chance at finding a home so I accepted her adoption of me as her human. ( I changed her name to DOLCE as it means "sweet")
I got used to her sleeping on top of me and waking me up at weird times not understanding why she would be so rude as to relentlessly make sure I was awake, even if her dish was full of food.
It was about a year later I was diagnosed as a diabetic. Sometimes she would let me sleep and other times she would pester me to wake up. I still didnt clue in as to why.
I was told to set my alarm for 3am to check my blood sugars by my Dr. as I was having strange numbers in the mornings and we needed to figure it all out. Thats when I noticed that when Dolce was trying to get me to wake up, my blood sugars were either really high or really low. I had heard of diabetic alert dogs but never cats!!!
Still thinking it was more of a coinicidence than anything, I didnt tell anyone about her little talent.
but from then on if she woke me up, I would check my blood sugars and sure enough I needed to wake up and take care of business.
Now that I am on insulin, and am still in the learning process she is even more diligent in waking me up before things get out of hand, and I cant tell you how much I appreciate her efforts.
I did not train her for this, it is just something she does on her own and I am truely grateful!