Horse Gender and Age Terminology Guide

Horse Gender & Age Terminology 101

When introduced to the horse world, it may seem like other equestrians are speaking a different language. While everyone will understand what you’re referring to when you say “baby horse,” “boy horse,” or “girl horse,” you may want to know the correct equine terminology to use when you’re at the barn. 

What is the correct gender and age terminology to use for horses? A baby horse of either gender is called a “foal,” while a female baby is called a “filly,” and a male baby is a “colt.” An adult female horse is called a “mare,” and an adult male horse is called a “stallion” or a “gelding” depending on his reproductive status. There are additional terms used to describe younger horses, older horses, and horses used for breeding.

There is a lot more to proper horse terminology than the words described above, so keep reading to learn everything you need to know to accurately identify any horse by gender or age.

What Is A Baby Horse Called?

A horse is not considered an adult until he or she reaches the age of four, but the term “foal” is generally only used to refer to a horse of either gender that is less than a year old.

From the ages of one to four, a “baby horse” is referred to by his or her gender – a “filly” for a young female horse and a “colt” for a young male horse who has not been castrated.

Of course, there are many reasons why one may want to denote the gender of a foal under the age of one. A female horse that is less than a year old may be called a “filly foal”, and a male horse that is less than a year old may be referred to as a “colt foal”. 

If this isn’t confusing enough, what a young horse is called may also depend on the age of the horse. A “weanling” is a foal that has been weaned – generally, this happens between 5 and 6 months of age.

A “yearling” is a young horse who has reached his first birthday but has not yet turned two – in other words, a horse between the ages of 12 and 23 months. A yearling may also be denoted by gender – for example, you may hear the terms “yearling filly” and “yearling colt”. 

Maybe I’m biased, but in my opinion, horses produce some of the most adorable babies on the planet! To learn more about the terminology used for baby horses and some fun foal facts, check out my article on what a baby horse is called.

female horse

What Is A Female Horse Called?

Once a filly reaches the age of four, she is an adult and is thereafter called a “mare.” Mares are not typically spayed like female dogs and cats, so the term applies to female horses regardless of reproductive ability. 

You may also hear the term “broodmare.” This is the term used to describe a mare that is used for breeding. Most broodmares are between the ages of 5 and 20, with the mid-teen years considered the “prime” age for healthy foaling.

Many refer to a broodmare who is caring for a foal as a “dam”, especially when referencing lineage (i.e. “Secretariat’s dam was Somethingroyal” – that is actually Secretariat’s dam’s name; though it does sound like I made it up for purposes of my example!) You can learn more about the terms used according to gender in my article about what a female horse is called.

male horse example

What Is A Male Horse Called?

A male horse over four years old who has not been castrated is referred to as a “stallion.” You may hear it said that a male horse is “entire” or “intact”—this refers to the horse’s testes, similar to a dog that is referred to as “intact.” A stallion used for breeding is called a “stud.” 

Most male horses who are used for pleasure riding or kept as pets or companions are castrated to decrease the chance of behavior problems associated with hormone fluctuations. Castrated male horses are called “geldings.” My horses, Tucker and Ruach, are both geldings!

This term applies to a horse of any age, meaning that if a colt foal is castrated at 9 months of age, he is thereafter referred to as a gelding.

That said, the line between the terms used for a colt and a very young gelding is especially blurry, and you may hear the two terms used interchangeably. To read more about the terminology used for male horses and the differences between geldings and stallions, my article about what a male horse is called.

Occasionally, one of a colt’s or stallion’s testicles will not have descended fully, rendering his castration mistakenly incomplete. When this happens, the improper castration may not be discovered until much later, often when unexplained stallion tendencies are displayed.

When this happens, the horse is called a “rig.” Rigs can be properly castrated when the discovery is made. A horse who has been properly castrated but still displays stallion tendencies is sometimes referred to as a “false rig.” 

Just as a mother horse is called a dam, “dads” also have their own terminology. The stud used in a successful pregnancy is called the foal’s “sire.”

Grandpas also have their own names – the sire of the sire (sire’s sire?) is called the “grandsire,” while the dam’s sire (i.e., maternal grandfather) is referred to as the “damsire.”

For another example – Secretariat’s sire was Bold Ruler. His grandsire (Bold Ruler’s sire) was Nasrullah, and his damsire (Somethingroyal’s sire) was Princequillo. 

An old horse

What Is An Older Horse Called?

An older horse is called a “senior.” At what age a horse is considered a senior is up for debate. Some call a horse a senior when he reaches 15 years of age, though honestly, I think of 15 as a prime age for most horses.

This older wisdom may have been more applicable decades ago when a horse’s lifespan was significantly lower than the 25 years on average that it is today. Others call a horse a senior when she reaches her 20s.

To me, this seems more appropriate, though a 20-year-old horse may have a decade of riding time left in her – one of my favorite Quarter horses will be forty years old this year and was ridden well into his 30s. 

Still others say that the term “senior” shouldn’t be used at all. The idea behind this opinion is that there is generally a bias against purchasing an older horse. Most people who buy horses do so in order to ride or show them.

A horse will, at some point, reach the age where these two activities are no longer feasible, and the horse will then need to be retired. Because every horse will age at his or her own pace, labeling a horse that is sound and in good health as a senior may cause some equestrians to unfairly overlook the horse. 

group of horses

What is a Group of Horses Called?

A group of horses is called a “herd.” Herds can vary in number, from two to more than twenty individuals. Herd dynamics are fascinating, and wild or feral herds give us a good idea of how our own horses communicate when together.

Horse herds are typically led by an alpha stallion and will include his “harem” (mares,) and their offspring. A “satellite stallion,” also called a “lieutenant stallion,” may be permitted by the alpha stallion to remain on the outskirts of his herd, offering additional protection from bachelor stallions and receiving limited breeding rights in return. 

Between the ages of two and three, a colt will be banished from his herd by his sire and will set up or join a “bachelor herd” with other colts and stallions who do not yet have their own harems or who have had their harems stolen by another. Most fillies decide to leave their family herds on their own, though some may choose to stay.

I love learning about horse herd dynamics. Not only is it interesting to me, but it helps me learn more about effectively communicating with the horses in my own life. You can read more about what horse groups are called here.

Using Proper Horse Terminology

Using the proper terms for a horse according to gender and age will not only help you to sound more experienced among other equestrians but will also help you more clearly and accurately communicate with veterinarians and other equine professionals.

There are a lot of different terms used in the horse world, (like all of these,) and if they seem overwhelming to you, don’t worry! You’ll begin to use all of these different terms naturally as time goes on.

And if you accidentally mix up the terms “sire” and “stud” when talking to horse breeders, know that they probably won’t even bat an eye (and if they do, they will likely enjoy correcting you!)

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Carmella Abel, Pro Horse Trainer

Hi! I’m Carmella

My husband and I started Equine Helper to share what we’ve learned about owning and caring for horses. I’ve spent my whole life around horses, and I currently own a POA named Tucker. You can learn more here.

Thank you for reading, and happy trails!

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