The term 'Small Slender Dog' can be summarized as a Whippet, which is a breed of dog that is known for its slender and athletic build. It is a medium-sized dog that typically weighs between 25 and 40 pounds and stands between 18 and 22 inches tall. The Whippet is a very fast and agile breed, making it an excellent choice for activities such as agility, lure coursing, and racing. They are also known for their gentle and affectionate nature, making them great companions.