Leaving animals out?

Im wondering, if i chose not to get any more pets/train my dog for herding, if there are negative effects to leaving animals out in the pasture overnight? I remember in one game, Island of Happiness I think, there were wild dogs that would come around and terrorize animals if there was no fence or something (its been awhile since i played either IoH or the original Grand Bazaar) is there a similar mechanic here or no? Would they just lose happiness? Tyia :)