What Do You Call a Female Horse? Filly, Mare, Broodmare, and Dam Explained

Last updated: April 13, 2026

By: Miles HenryFact Checked

A friend of mine once asked why I called one of our young horses a filly instead of a mare. It’s a fair question — most people outside the horse world assume “mare” covers everything. It doesn’t. Female horses are called different things depending on their age and what they’re used for, and once you know the distinctions, you’ll hear them constantly in racing, breeding, and general horsemanship.

The short answer: females four and under are fillies, females five and older are mares, females kept for breeding are broodmares, and a mare’s identity as a mother is specifically captured by the term dam. Whether you’re just calling them “girl horses” or want the proper terms, each word means something different — and using them correctly tells people immediately that you know horses.

I’ve been around horses for more than 30 years in Louisiana — owning, racing, and breeding Thoroughbreds. These terms come up every single day, whether I’m reading entries at the track, reviewing a breeding contract, or just talking to someone at the barn. Here’s what each one means and when to use it.

Filly: Young Female Horses

In Thoroughbred racing, a filly is any female horse four years old and under — she becomes a mare when she turns five, as defined by The Jockey Club’s American Stud Book, the official registry for Thoroughbreds in the United States and Canada. In most other breeds and disciplines, including American Quarter Horse Association conventions and general equine industry usage, the cutoff is a year earlier — a female horse is a filly under four and a mare once she turns four. So if someone tells you a four-year-old is a mare, they’re not wrong — they’re just using the broader standard rather than the Thoroughbred-specific one.

You’ll hear the filly designation constantly at the track — races are often split between colts and fillies specifically because young females compete separately from young males at certain levels. Some of the best racehorses in history were fillies. Ruffian was one of the greatest American racehorses ever, male or female. Winning fillies are a regular feature of major stakes races, and their performances are tracked separately in racing history precisely because the term has real competitive meaning — not just an age label.

Within the filly category, there are more specific terms that come up depending on the horse’s stage of development:

• Suckling filly — a female foal still nursing from her mother, typically under six months old
• Weanling filly — a female foal that has been weaned from her mother and is eating independently
• Yearling filly — a female horse between one and two years old; this is the stage where Thoroughbred sales like Keeneland and Fasig-Tipton do most of their business

If you’re still deciding on a name for a young filly, we put together a list of 237 girl horse names that might help.

Mare: Adult Female Horses

A female horse becomes a mare once she reaches adulthood — the exact age depends on the context. In general equine use and most breed registries, including AQHA, a female horse is a mare when she turns four. In Thoroughbred racing, the cutoff is five — that’s the standard in race condition books and Jockey Club records. Either way, the word comes from the Old English meare and has described an adult female horse for centuries. If you’re asking what do you call a female horse once she’s grown, mare is always the right answer.

Mares are used for everything a male horse is used for — racing, ranch work, trail riding, and competition at the highest levels of sport. I’ve raced and ridden mares my whole career. They can be as competitive and capable as any horse on the property, and the best ones will let you know exactly what they think about the situation. That’s not a flaw — it’s usually a sign of intelligence.

That said, mares have their own temperament. In my experience they’re more opinionated than geldings — they’ll show you when something’s off rather than just going along with it. I currently have a young filly that is more difficult to handle than any colt I’ve been around. Gender is one factor, but individual personality always matters more than the general rule.

Broodmare and Dam: Breeding Terms

A broodmare is a mare whose primary job on the property is producing foals. She may be a retired racehorse, a proven show horse, or simply a mare with bloodlines or traits worth passing on. In the breeding barn, broodmare is her job designation — it tells you her role, not her personality or her history.

That doesn’t mean broodmares are retired from everything else. We’ve had mares we continued to use for pleasure riding even while they were in foal, within safe limits. The term describes her primary purpose, not a restriction on what else she can do.

Dam is more specific still. It refers to the mother of a particular foal — it’s a pedigree term, not a general label for any female horse. When you read a Thoroughbred sales catalog or a breeding record, the dam is listed alongside the sire to document the foal’s parentage. You wouldn’t walk up to a mare in a field and call her “the dam” unless you were referring specifically to her relationship with a named offspring. She becomes a dam the moment she produces her first foal, and that designation follows her in every breeding record from that point forward.

For more on what the transition from racehorse to breeding mare actually looks like, the article on when racehorses retire and what they do next covers that in detail.

Female Horse Terms by Age — Quick Reference

Here’s how the terminology maps across a female horse’s life from birth through adulthood:

Term	Age / Stage	Notes
Filly foal	Birth to weaning (~4–6 months)	Also called a suckling filly while nursing
Weanling filly	~4–6 months to 1 year	Eating independently; no longer nursing
Yearling filly	1–2 years old	Key sales stage for Thoroughbreds and Quarter Horses
Filly	Under 4 (general) / 4 and under (Thoroughbred racing)	Age cutoff varies by breed and discipline
Mare	4 and older (general) / 5 and older (Thoroughbred racing)	Adult female horse regardless of use
Broodmare	Any adult age	Mare used primarily for breeding
Dam	Any adult age	The mother of a specific foal — pedigree term

What About Baby Horses in General?

A foal is any baby horse regardless of gender. Female foals are filly foals; male foals are colt foals. The distinction between filly, colt, and foal trips people up regularly. For the full breakdown of baby horse terminology — including when foals are weaned, how fast they grow, and what to expect in the first year — the complete baby horse guide covers all of it.

Also worth noting: a pony is not a baby horse. It’s a separate classification based on height, not age — a common misconception.

Below is a YouTube video of a mare and her filly.

FAQs: What Do You Call a Female Horse?