Death of older dog

Question
I had a 16 year old cocker spaniel who died yesterday while I was at work.  She had been at the groomers the day before which is a little hard on her because of her age.  But she acted normal that evening.  She ate dinner, etc.  The next morning same thing, normal ate breakfast, went outside, came back up the stairs by herself (sometimes she can't and needs help).  She has been panting hard for a long time and has been overweight most of her adult life.

When I came home from work yesterday.  She didn't greet me at the door.  I looked around and found her laying on the floor at the foot of my bed.  I then saw that she had defecated in her dogbed.  When I looked closer at her she had blood on her foot and around her mouth and she wasn't breathing.  

Can you tell me what happened?  I know she was old but why the blood?

Answer
Oh Rose Marie this is so hard! I know that horrible feeling when you realize she wasn't breathing.

It's quite possible that she died from old age but often a vessel near their heart will just give out, which then bleeds into the lungs, and then out the mouth. Often they have "silent" cancers like hemangeosarcoma which will rupture and then bleed out. Her panting could have been from her heart going for a long time and then it just stopped. Sometimes the blood is just from them biting themselves as they are dying, sort of a reflex that they don't feel. I'm so sorry!!

But 16 is very old for a Cocker, so she pretty much lived her full life and died of old age.
You gave her a full and wonderful life, so celebrate your years together.

I know it's very hard. My thoughts are with you.