Congenital deafness can be genetic , seen sometimes in dogs with merle or white coats , or caused by in utero damage from infections or toxins .
先天性耳聋可以是遗传性的，见于云石色系或背色被毛犬，或者是感染或毒素引起的宫内损伤所导致的。
In all the books I have read on Border Collie history , I have never seen a reference to a merle as a herding champion either in Britain or in the USA.
