Shelties have a double coat, which means that they have two layers of fur that make up their coat. The long, rough guard hairs lie on top of a thick, soft undercoat. Shelties have a double coat, and often shed a lot of the time, no matter the season. Male shelties technically shed less than females but fur still comes off constantly. Shaving these dogs is very bad for their skin and some do not regrow any significant amount of hair after being shaved, a condition known as alopecia. Spaying or neutering can alter coat texture, making it softer, more prone to matting and even more profuse. Shelties shed in clumps which can be pulled or brushed out of the main coat, rather than individual hair. His research found that an average Sheltie could understand a new command in fewer than five repetitions and would obey a command the first time it was given 95% of the time or better.