Dandie Dinmont Terriers are small, sturdy dogs. They typically stand about 8 to 11 inches (20 to 28 cm) tall at the shoulder and weigh between 18 to 24 pounds (8 to 11 kg). Their unique appearance is characterized by a long body and a distinctive "topknot" of hair on their heads.

Dandie Dinmont Terriers are known for their friendly, affectionate, and intelligent temperament. They tend to be loyal and devoted to their families, often forming strong bonds with their owners. They can be alert and playful, but they might also show a stubborn streak, so consistent training and socialization from an early age are essential.

The breed has a distinctive double coat, characterized by a rough, wiry outer coat and a softer undercoat. The coat is commonly found in two main color patterns: mustard (a golden yellow) and pepper (a dark bluish-gray). Regular grooming is necessary to maintain their coat and minimize shedding.

Dandie Dinmont Terriers adapt well to various living environments, including apartments and smaller homes, as long as they receive regular exercise and companionship. They do not like being left alone for long periods and thrive on social interaction with their families.

These terriers require regular exercise to stay fit and happy. Daily walks, playtime in a secure area, and interactive games are essential for their well-being. They enjoy activities that engage their natural hunting instincts, such as scent work and tracking. Dandie Dinmonts can also participate in dog sports like agility and obedience training, which provide mental stimulation and help strengthen the bond with their owners.