Borzois are large Russian sighthounds that resemble some central Asian breeds such as the Afghan hound, Saluki, and the Kyrgyz Taigan. Borzois come in a variety of colours. The Borzoi coat is silky and flat, often wavy or slightly curly. The long top-coat is quite flat, with varying degrees of waviness or curling. The soft undercoat thickens during winter or in cold climates, but is shed in hot weather to prevent overheating. In its texture and distribution over the body, the Borzoi coat is unique. There should be a frill on its neck, as well as feathering on its hindquarters and tail.