When I bo't my Shetland she's was wearing a fairly heavy "sweater", in summer. Previous owner tho't that because she was built like a little tank, she didn't need deworming. I promptly dewormed her and within a month she started dropping her old winter coat. She was dewormed again thro the winter and in spring shedded out to a beautiful chocolate dapple. My qh seems slow to grow his coat as it's fine. By late winter he has long shaggy hair on his chest, elbows and lower belly. In summer his coat is short and slick. My TWH has coarse hair. His just lengthens all over. In summer, altho he shines like polished coal his coat doesn't get real slick like the other. Different hair texture.