so your saying failed rabbit dogs make good deer dogs,I think you need to bear in mind that we are talking working collies, not collie cross lurchers. I think that the collie brain gets used to rabbits fecking off down holes, cover etc. Then some start to run clever and pick their runs. Deer are too different in that they stay above ground and are more visible when running when due to their size. It takes a bit more for a determined dog to give up on one compared to a rabbit, if that dog is a thinker. I have heard and thought, in the past, that the similarity of deer to sheep was what created