This is the problem. One of my lurchers toe nails grow fast as feck(front ones only) the back ones are ok. My dogs get a least 1 hour each every day road walking. I have no problem with my other lurcher(his nails are transparent)The problem nails are the ones on the outer and inner of his front paws. The ones on the two middle toes grow to a point, but the ones on the inner and outside grow the same thickness all the way down. I cant see where the quick is in his nails as they are black, im a little bit nervous when cutting his nails incase i go to far down. Tried shining a touch through them,