ker

1. colloq. (of the animal) dog; mutt
   Komšijin ker laje celu noć. — The neighbour's mutt barks all night.
   Pazi, onaj ker ujeda! — Careful, that dog bites!
2. derog. (of a person) dog; scoundrel
   Taj ker me je prevario za pare. — That dog cheated me out of my money.
3. slang derog. (usually plural) cop; pig
   Beži, eno kerova iza ugla! — Run, there are cops around the corner!

As "dog" it is colloquial and can sound rougher and more dismissive than the neutral pas, but it is not necessarily derogatory.