(1) A nonspecific term for any condition that affects multiple arteries. (2) Polyarteritis nodosa, see there. (pol'Ä-ahr'tÄr-Ä«'tis) Simultaneous inflammation of a number of arteries. inflammatory and degenerative lesions of the arterial walls in a number of isolated locations.
The Border Collie comes in two coat varieties: rough or smooth. Both varieties are double coat and weather resistant and are close fitting and thick. The outer coat is either wavy or straight and coarse in texture. The under coat is dense, short, and soft. The rough coat variety has fur of medium length.
Its worth noting that dilution alopecia is very rare in all breeds and especially so in border collies. I have bred and met hundreds of blue and lilac border collies and have only ever seen one affected with this condition, while visiting a dog show out on the continent.