What Is a Colt Horse?

Mare looking at her pinto colt.
A mare looks at her pinto colt. Image Credit:Rachelle Vance Photography/Moment RM /Getty Images

Shoe the horse and shoe the , but let the little colt go bare.

You often see or hear the word colt used to refer to any baby horse. But this is incorrect and there are specific words to designate the gender of a young horse. The word foal is the correct gender neutral word to use for a baby horse.

Definition of Colt: A cold is an uncastrated male horse, pony, donkey or mule under four years of age.

Pronunciation: k o lt (long o sound--rhymes with bolt)

Also Known As: The world colt is often incorrectly used as a synonym for the word foal.

Examples: The colt and filly played in the paddock while their mothers grazed nearby. While the sentence could have read "The two foals played in the padddock," the first tells you the gender of the foals. 

Characteristics of Colts

Many people feel that fillies are smarter than colts foals. Some believe they’re quicker to stand and nurse after they are born. This may be a myth.  Many people believe that colts are bolder than fillies but a 2010 study suggests that this too may be untrue. Colts tend to grow a bit faster than fillies, and even more so if they are gelded young, which sends growth into physical growth rather than reproduction ability. 

Anyone who buys a colt needs to know that they should commit to gelding the colt as soon as possible.  There are many good reasons why you should geld your colt.  Even though a colt may be very young, they may still be able to reproduce, which can contribute to the problem of unwanted horses. Owners need to think very carefully about keeping animals for breeding.

Common Incorrect Usages of Colt

It is common to refer to all baby horses as colts, but that this is not correct. It’s often heard in movies and in books. A female baby horse is a filly and a male is a called a colt. All colts and fillies may be called foals. Foal is the correct way to refer to any young horse still with a mare, who's gender is not known. Very young horses may be called filly foal or colt foal. When a colt is weaned it may be called a weanling colt, and when it reaches the age of one, it may be called a yearling colt, or just a yearling.  You might hear a colt over the age of one or two called a stud colt.

Horse Racing

In the horse racing world, a colt is a young male horse between the ages of two and five. There are usually races for colts and for fillies. After the age of five colts are called either stallions or geldings. In a  race, a filly may be any female horse running under the age of five years old. After the age of four, a filly will be a mare.

All equids including donkeys, ponies,  mules, zebras, and onagers may be referred to as colts or fillies as well. So you might hear someone talking about a donkey filly or pony colt. 

Roots of the Word Filly

The word colt comes from an Old English word and is similar to a word in Swedish dialect kult which means half-grown pig. According to the Mirriam-Webster dictionary, the word was first used in the 12th century.