Small dog breeds are typically defined as dogs that weigh 20 pounds or less. These breeds are popular for their compact size, making them suitable for apartment living and easy to transport. Common small dog breeds include the Chihuahua, Pomeranian, and Yorkshire Terrier. They often have lively personalities and can be very affectionate companions. Despite their small stature, many small dog breeds are known for their energetic nature and intelligence. They require regular exercise and mental stimulation to stay healthy and happy. Small dogs can also be prone to certain health issues, so regular veterinary check-ups are important for their well-being.