Question

why was the invisible man afraid of dogs ?

Answer 1

Fearenside is a man who hauls luggage that belongs to the stranger. He tends to see the positive rather than the negative. Some would call him simple but there is a kindness about him.  His dog gets upset at the stranger and attacks him, ripping his pants, exposing his dark leg. Later when Fearenside discusses this happening with Henfrey, he just assumes that the stranger, who has a pink nose and black legs must just be multi-colored like a "piebald horse." This is a relatively charitable statement, assuming that which is more positive than negative.