|Dog (domestic dog)|
The Borzoi[a] or Russian Hunting Sighthound[b] is a Russian breed of hunting dog of sighthound type. It was formerly used for wolf hunting,: 125 and until 1936 was known as the Russian Wolfhound.: 130 
The system by which Russians over the ages named their sighthounds was a series of descriptive terms, not actual names. Borzói is the masculine singular form of an archaic Russian adjective that means 'fast'. Borzáya sobáka ('fast dog') is the basic term for sighthounds used by Russians, though sobáka is usually dropped. The name psovaya derived from the word psovina, which means 'wavy, silky coat', just as hortaya (as in hortaya borzaya) means shorthaired. In modern Russian, the breed commonly called the Borzoi is officially known as russkaya psovaya borzaya. Other Russian sighthound breeds are stepnaya borzaya (from the steppe), called stepnoi; and krimskaya borzaya (from the Crimea), called krimskoi.
The Borzoi originated in sixteenth-century Russia by crossing Persian greyhounds and European sighthounds with thick-coated Russian breeds.
The more modern Psovaya Borzaya was founded on Stepnaya, Hortaya and the Ukrainian-Polish version of the old Hort. There were also imports of Western sighthound breeds to add to the height and weight. It was crossed as well with the Russian Laika specifically and singularly to add resistance against Northern cold and a longer and thicker coat than the Southern sighthounds were equipped with.
All of these foundation types—Tazi, Hortaya, Stepnaya, Krimskaya, and Hort—already possessed the instincts and agility necessary for hunting and bringing down wolves.
The Borzoi was popular with the Tsars before the 1917 revolution. For centuries, Borzoi’ could not be purchased but only given as gifts from the Tsar. Grand Duke Nicholas Nicolaievich of Russia bred countless Borzoi at Perchino, his private estate.: 10 
The Russkaya Psovaya Borzaya was definitively accepted by the Fédération Cynologique Internationale in 1956.
Borzois are large Russian sighthounds that resemble some central Asian breeds such as the Afghan hound, Saluki, and the Kyrgyz Taigan. Borzois come in virtually any colour. 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.
The Borzoi is an athletic and independent breed of dog with a calm temperament.
In terms of obedience, Borzois are selective learners who quickly become bored with repetitive, apparently pointless activity, and they can be very stubborn when they are not properly motivated. For example, food rewards, or "baiting", may work well for some individuals, but not at all for others. Nevertheless, Borzois are definitely capable of enjoying and performing well in competitive obedience and agility trials with the right kind of training.: 113 
Stated life expectancy is 10 to 12 years. Median lifespan based on a UK Kennel Club survey is 9 years 1 month. 1 in 5 died of old age, at an average of 10 to 11.5 years. The longest lived dog lived to 14 years 3 months. Dogs that are physically fit and vigorous in their youth through middle age are more vigorous and healthy as elderly dogs, all other factors being equal. In the UK, cancer and cardiac problems seem to be the most frequent causes of premature death.