Symptoms of a dislocated shoulder in a dog?

My dog got his shoulder dislocated last week.

We took him to our vet and they took an x-ray and a very
short time later they knew.

Here are his symptoms prior to the x-ray:.

He was holding one leg up and panting. He seemed in shock
and was trembling. There was no doubt at all that he was
in distress and in extreme pain.

His eyes were droopy and they were full of tears and you can
see a lot of pain in them.

Lifting him into the car was very difficult. The paw that is connected
to the injured shoulder was super sensitive. Had to drive very
slow since he would yelp at every bump in the road no matter how
small.