Thank you for using this site to help you with your problem. My name is XXXXX XXXXX X have been in the dog field for 25 years. It will be my pleasure to help you today.
Do you know if it started out of fear or pain?
No, not fear, but possibly pain. She is also drooling.
She is laying down now and breathing really heavy.
What color are her gums and if you press and release your finger on them how long does it take to go back to normal color?
they look black
thank you. have they always been black?
I not sure really??/ But they do not change color when I press on her gums
I would have to say that because of her age and her breathing and the fact that the gums are not blanching you contact your vet tonight or an ER vet.
Do you have an idea of what it could be?
Not really , pain anywhere can show panting and trouble breathing and shaking can be from pain as well. Dogs this size are prone to disc disease which is painful and they are prone to pancreatitis which is painful
I am sorry , I am worried for her. May I send you a free follow up in a few days to see how she is?
I'll sign of so you can go put a call in to your vet