Found my cat DEAD!!

Question
Hello my name is Emily and recently buried my cat of 7 years. My neighbor came to me today and asked did i have a cat she said there was one dead in her back yard. I replied no it's not ours they are inside cats that are intimidated by all the rest of the neighborhood cats(20 to be exact!)My cat would love to go out and play in our trees, come back in to the sound of the door opening and that's about all.  It's a mystery why our little "TAZ" was dead in her back yard. I found in nestled lying on his tummy with his face between his two paws as if he was sleeping. He had blood in his mouth and one the ground where his face layed.We was lying very close next to the fence so close you could see him on the other side of the fence ( where the fence meets the slab of cement.I just don't understand what i did wrong. I never seen this coming. I thought he was inside all day when i was away.we are unsure if he was poisoned, hit by a car(the road is not near). if he was dying, why wouldn't he come home.. i am so confused and very sad, he has a sister so anytime i see her i see him. This is my second cat i lost and it doesn't get any easier.What are the signs of a poisoned cat? What is your conclusion? Do you think he was dumped over the fence? Or hit by a car and had trauma of some sort and died slowly. His body looked undamaged, despite he was very swollen and stiff. He did have feces under him too. Can you please help me figure out this mystery so I can finally be at rest with this. Thanks, Emily in CA.

Answer
Emily,

I am so sad for your loss.

The only way to find out how the cat died is to have a vet do a necropsy.  Even then it does not always tell exactly what happened.  Of course you are right to keep these cats indoors!!!!!

Cats can swiftly run out while you have a door open and are not looking.  One just must always be diligent that the cat does not run out the door when you are leaving or arriving home.

I would also check for slightly opened windows.  It seems amazing what small spaces cats can get through.

Sad regards... Norm.