yes. all dogs do this is perfectly normal DO NOT DISCOURAGE THIS ACTION
they do it to get rid of excess hair and they normally put their tails between their legs
He is obviously scared. When a dog holds a tail behind its legs then it is scared.
run away with their tails between their legs
They lose their tails, not legs.
Because hes scared
A cat tucks its tail between its legs when scared or threatened as a way to protect itself and signal submission. This behavior helps the cat appear smaller and less threatening to potential threats.
Yes, it is scared that he will have an operation too.
a quarter
They usually keep them between their legs when they're depressed or scared.
to show how they feel. if its tucked in between its legs then its scared or unhappy. if its wagging then its exited or pleased.
One has a shell and its gills are under their shell. But regular fish have gills next to their mouths and have tails and swim around. Also I think shellfish have legs or no legs but I don't believe that shellfish have tails but regular fish have no shell and a tall.
This could be pain, although most dogs in that much pain won't walk around very much. It is more likely to be the dog signalling submission and fear/anxiety in general. A professional dog trainer may be able to help you address this so your dog is less fearful.