Facebook post by University of Helsinki

Millennia of breeding has created a veritable rainbow of dog breeds but at the same time negative characteristics have also become heightened. Now the canine genetic research progresses in leaps to detect problems causing diseases. The findings can help people's health too.
Dogs walking six minutes for science – researchers are studying diseases in over-bred varieties | University of Helsinki helsinki.fi

Breeding has narrowed the genetic variation in some dog breeds to the extent that all individuals are effectively identical twins of one another.