How many times have you heard people use the term colt for baby horses? Perhaps it happens all the time because there is a lot of confusion swirling around it.

Normally, animals have two different names to describe their youth and adulthood. Nevertheless, it’s a bit different with horses as they have distinct names for each stage of their development. 

Some of these names are colt, foal, and fillies. These names are determined by their age and gender—no wonder people are always confused about them. However, as a true horse enthusiast, you should be aware of the names so that you are never in the dark again while talking about horses. 

Here, we will discuss the colts in detail—their characteristics and some overlapping terms that are closely associated with them.

What Is a Colt Horse?

If we specifically look at the answer to this question, a colt is a male horse under the age of four. It is usually not castrated, which means that it can be used for breeding. On the other hand, all-female horses under the age of four are labeled as fillies.

However, if we look for a general term that can be used for any horse baby, regardless of gender, it is foal.

So, the term foal can be used for all horse babies—colt and fillies. You can also refer to a baby horse as filly foal or colt foal if you want to specify the gender.

The colts are not only young, but they are also not castrated. After the age of four, the colts are labeled as stallions or full horses—they can be used for breeding in the latter part of their life. 


The word colt has its roots in old English, which means ‘young ass.’ There are similar words in Swedish and Danish as well—kult and kuld, respectively—with similar meanings like offspring, boar, or boy.

However, other baby animals like donkeys, ponies, zebra, or mules can also be called colts—if they are male and under the age of four.

Common Usage of Colt

It is really common to refer to any young horse as a colt. The mistake is so prevalent that we often encounter it in movies and books as well.

Also, the term colt is used for horses that are not castrated. If the horse is castrated, then the proper term to use is gelding.  

After the age of four, a colt is described either as a stallion or gelding. On the other hand, the female horse after the age of four is called a mare.

Colts in Horse Racing

In the horse-racing world, the definition of colt is a bit different because young horses between two to five are described as colts. After the age of five, they are registered in horse racing just as horses. However, castrated horses are still called geldings.

Characteristics of Colt

Colts do many tasks and take part in racing too. They grow up quickly and are helpful for racing, farming, and riding. They can also be used for breeding at this stage, although many owners decide to wait for a little longer until they are fully grown up.

There are a lot of myths about colts being brighter than fillies or fillies being bolder than colts, but there are not enough and authoritative studies to support such myths. There might be minor differences in skills or speed, but both colts and fillies excel in their respective areas.

Why are Colts Castrated at a Young Age?

Many horse owners castrate—the process of removing testicles—their colts at a young age. There are many reasons for this. For instance, castrated horses are less aggressive and easy to train. Also, they are more likely to win races without the interference of reproductive hormones.

Castrating early in their life is important because delaying the process can be risky as colts start developing stallion-like aggressive behavior and can become difficult to handle. To be on the safe side, they are castrated before developing any spoiled behavior.

What Is a Yearling Horse?

A horse before his second birthday is referred to as a yearling, regardless of gender or castrating.

At this age, the bodies of yearlings are adequately developed, which means they are not suitable for riding or breeding.

What Is a Weanling Horse?

A weanling is a horse that has been recently weaned. Horses are weaned at the age of three to five months. This is a gender-neutral term and can be used for male or female baby horses.

What Is a Stallion?

A stallion is a horse above the age of four that has not been castrated, and most probably, the owner will use it for breeding. Moreover, owners use their best winning horses for breeding to pass on the best qualities to the next generation. When a stallion is used for breeding actively, it will be described as a stud.

What Is a Mare Horse?

Mare is a female horse above the age of four or five. They are also used for racing as they are easily trained. However, many prefer male horses for races as mares can be a little moody. 

What Is a Pony?

Ponies are not baby horses. The name is referred to horses that are small or midget. They are less than 14.2 hands in height.


Whether you are new to horse racing or wishing to have a horse as a pet,  you should know what a colt is and what differentiates it from foals and fillies. In this article, we thoroughly explained the facts and myths about colts, fillies, and foals so that you can understand your horses better.

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