I have a 3 year old lab that is very hyper active full of energy dog and for the last 3 days it has not ate and can bearly make it up the stairs I even went out and bought different food thinking maybe she does not like her food anymore she will not eat that either. She seems very sore and is shaking while standing. If anyone has any help it would be appriciated Thanks Phil

Phil, if your dog hasn't eaten for 3 days and she has developed physical symptoms as you have described, it is time to get her to your vet ASAP.

She might have eaten something that is causing a blockage or she might have picked up a virus. It could be anything. Without being able to examine her, no one can properly diagnose your dog online. Please, I am begging you, do not wait around for answers and get her to your vet before the end of the day. If you remember to do so, please post back and let us know if she is okay.

Agree with everything JAL has said, it's time for the vet I'm afraid.
Any sudden changes need to be looked at by a professional and intestinal blockages is certainly a common problem that need to be acted upon fast!