filly

In English-language horse terminology, a filly is a young female horse, typically under four years of age. The term is used to distinguish her from a colt, a young male horse. When a filly reaches about four years old, she is usually referred to as a mare, though the exact age at which the term changes can vary by breed, discipline, or regional usage.

Within a filly's early life, common terms describe stages of growth: a foal refers to a newborn or very young horse, a yearling is one year old, and a weanling has recently been weaned. A filly may be described as a yearling filly or weanling filly as appropriate.

Uses and roles: Fillies are kept for breeding stock and may become broodmares once mature. In sport and racing, fillies may compete in events restricted to female horses under four; some races allow fillies to compete against colts at younger ages or in mixed-age events, depending on rules.

Care and management: Like other young horses, fillies require proper nutrition, regular veterinary care, vaccinations, hoof care, and dental checks. Gentle, progressive handling and training that suits their age support sound development and can help reduce the risk of injury. As they mature, decisions about training, discipline, and breeding are guided by temperament, health, and performance goals.