My dog died suddenly, without any warning:

[Aimee2612]

I was hoping someone may be able to answer what happened to our 11 year old pit bull, Kitty.  She died suddenly this past Saturday, 11/15/14.  She was acting normal, and we were going to the mountains to camp for the night.  When we arrived, she got out of the truck and roamed as normal.  About 15 minutes later she started acting strange.  She wanted to get back into the truck.  We let her in the back, and she laid very still on the seat.  She immediately seemed lethargic and started having labored breathing, and lost control of any motor skills.  Her tongue just hung from her mouth.  It seemed almost as if she was stunned.  I watched her pupils take over her eyes, her breathing slowed, and she was gone within 20 minutes.  It is going to hurt for a long time.  I guess it would give us some peace to have an idea what happened to her.  There was nothing we could do to save her.

[shortysquid]

She may have been bitten by something out there. As well, some dogs the older they are can just pass from old age. I'm sorry I can't help you more.

[Margot49]

So very sorry to read this.  I see you are in AZ, I assume you might have been in an area where there might be snakes, scorpions,spiders?  I would suspect a bite and, if she wandered off too far and yelped, you may not have heard her.  That is only a guess and no way to tell for sure unless you had a necropsy done.  Just a tragic situation.  Again, so sorry.

[Melanieparker]

Is there any bite wounds in your dog's body? It is possible that he got bitten by some venomous snakes. Here are the cardiopulmonary symptoms when dogs are bitten by snake, it the same to what your dog displayed.

1. Hypotension (low blood pressure)
2. Low rate respiration
3.Lethargy

You dog is in rainbow bridge now. Just imagine how happy he is right now playing with his pals. :)