Wild harvest mouse dies in my hands

Question
I found what I think is a harvest mouse in my garden last night.  It ran along the path by my house then darted under a large flower pot.  It was a very quiet evening and I was suddenly aware that I could hear it squeaking.  It sounded distraught.  I moved the flower pot and found the tiny mouse was on its back, seemingly convulsing, with its legs in the air.  It squeaked a few more times and so I picked it up.  I also noticed that it had urinated too.  Just a tiny speck, like an amber bead.

He curled up in my hand, quiet, but still shaking.  Moments later he closed his eyes and stopped breathing.  I was, and still am, really upset about it.  

I know its too late to ask for help which might have saved him. Perhaps nothing could have.  But what do you think was wrong with it?  Had it fallen from somewhere, started to run and then realised it was more injured than it had first thought?  Had I scared it when I walked along the path too?

I realise that your expertise is with pet mice, but I just wondered if you would have any idea about what might have caused this poor little fellow to die so suddenly...

Many thanks,
Sarah x

Answer
Dear Sarah,

For the most part, mice get the same illnesses as people. Thus anything that can kill a person suddenly could also kill a mouse. Possibly a heart attack, since that is painful.

Also, it is completely normal for a mouse to lie on its back, convulse, and urinate at the moment of its death, no matter what it is dying of. It is only the squeaking that makes me think it was in some kind of pain beforehand.

In any case, there was absolutely, absolutely nothing you could have done; nor a vet. It was too late.

And without an autopsy you will never be able to know what killed it.

But at least you can feel better about the convulsing and urinating. That is what happens when a mouse dies.

And a well mouse never lies on its back.

I'm sorry you had to experience this. And I am sorry for any pain that the mouse may have felt. I hope it was quick.

Thank you for caring.

squeaks,

Natasha