Shetland sheepdogs, or shelties, are small herding dogs with the coat and appearance of the larger collie. The Scottish breed has a long, rough double coat that can take as many as five years to mature. How long a sheltie's fur grows depends in part on genetics, though sheltie owners can encourage fur growth in each stage of development.
Shelties are virtually unrecognizable as puppies. Their fur at two to three months is thick but short, at around 1 inch in length. The fur on their heads begins growing out first. At five to six months, shelties look lion-like, with a mane of longer fur framing the face. The fur on the rest of the body stays short until adolescence, which begins at around six months. Though their coats have yet to fill out, shelties have their black, white and tan color patterns at birth.
At six to 12 months, the sheltie's ruff, or the fur around the neck and chest, starts to thicken and grow long, reaching about 6 inches. At around 1 ½ years, the topcoat on the back and the fur on the upper halves of the legs grows noticeably longer, to about 2-3 inches in length. The coat develops until ages three to five. At maturity, your sheltie's undercoat should still be soft, short and dense, while the topcoat should be rougher and up to 6 inches long all over the body, including the tail. Shelties keep the short fur on the bottom halves of their legs.
As adults, shelties maintain their full coats, but they're prolific shedders and go through one to two heavy blowouts a year. Most spayed females and unneutered males shed their coats once a year, in the spring. Because of hormonal differences, males shed less often than females. Neutering your male sheltie will cut back on shedding even more: Some fixed males shed heavily as little as once every two years.
Promoting Coat Growth
Spayed shelties shed less than their unaltered counterparts, so altering your dog at an early age will improve coat preservation and development. Providing healthy food supplemented with copper, zinc and omega-3 fatty acids can also help fur growth. Brushing your dog can keep its coat healthy, distributing conditioning skin oils and encouraging new fur growth. Mix water and a small amount of hair conditioner in a spray bottle and mist your sheltie's coat before brushing. Comb first against the topcoat's direction, to get at the undercoat. Missing the undercoat allows matts and knots to build, which can cause infected hot spots on the skin. Pay special attention to the bases of the ears and the armpits, as knots build in those areas. Brush your sheltie one to two times a week, or more during heavy shedding periods.