Make sure you do as much research and reading on the bread as you can. They take more care than short hair bread. Make sure you go to a reputable breeder of Old English Sheepdog. Get information from the Kennel club
Old English Sheepdogs: What's Good About 'Em
The Old English sheepdog is a breed, or type, of dog known for its long, shaggy hair. The dog is sometimes called a bobtail because the tail is bobbed, or cut very short, soon after birth.
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A bearlike breed of herding dog, the Old English sheepdog is known for its very thick, shaggy, gray and white coat. Its ears are long, pendantlike, and shaggy. The tail is docked extremely short when the dog is about 4 days old, so the dog looks tailless; it is also called the bobtail. The eyes are large, deep-set, and either china blue, brown, or one of each. An adult Old English sheepdog stands 21-25 inches (53-64 centimeters) tall at the shoulders and weighs 55-65 pounds (25-29 kilograms). The breed probably developed in the early 19th century in western England from eastern European dogs and was used for driving sheep and sometimes cattle to market. The tails were docked because this breed was exempt from taxation, and docking the tails was a way of keeping a record of this. Old English sheepdogs were not groomed but were often sheared annually in the spring along with the sheep, and the hair was spun into cloth. The coat protects the dog from heat, cold, and dampness. The dog is known for its adaptable, even-tempered disposition.
Old English Sheepdog Dog Breed Information - American Kennel Club