my dog is always aroused

[COL OR=blue]blue[/COLOR] my mini pincher ran away then came back 24 hours later beat-up and scared,he is eating ok but in pain, my question is part of his penis is exposed and has not retracted,why has this happened and what can i do,please help

Sounds like he had some mishap with a female dog...I assume he is intact?

Priapism (the penis not retracting) can be extremely painful and lead to a bad infection. He needs to be seen by a vet right away, IMHO - and he really ought to be neutered too.