Male Horse

There are a number of different terms for a male horse, depending on its age and whether it has been castrated:

  • Stallion.  A male horse over four years old, which has not been castrated. 
  • Stud. A stallion which is being used for breeding or that is available for breeding. One also sees the terms 'stud stallion' and 'stud-stallion'.
  • Gelding. A male horse which has been castrated, regardless of age.
  • Colt. A male horse under the age of four. Some people use this term for both female and male horses under four, but correct use is for a male only.
  • Ridgling (or rig). A male horse which has has an undescended testicle or has been improperly castrated is called a ridgling. It will appear to be a gelding, but will have some of the behaviours of a stallion.
  • Yearling - Used for a horse (female or male) which is between one year old and two years old. Some people follow an alternative definition, which is a horse approximately one year old.
  • Foal - A horse (female or male) which is less than a year old. A nursing foal is sometimes called a suckling and a foal that has been weaned is called a weanling. Most domesticated horses are weaned at 5 to 7 months of age, although commercial breeders often wean much earlier. 

For comparison, see also female horse.


The age definitions are interpreted differently depending on who is using them. For example, a colt may be defined as under 4 years of age, but some horse organisations define a colt as being under 3 years of age while others use 5 years.

When calculating age, racing organisations tend to use a specific date (e.g. 1st January) regardless of the actual birthday. For example, a horse born on 1st May 2009 would be considered a year old on 1st January 2010 (rather than on 1st May 2010). The reason for this is that some races are for specific ages (e.g. 3-year olds only), while other races which accept multiple ages will handicap horses differently depending on their age. To have to track each horses actual birthday to determine if it is eligible to race and to calculate its handicap would be complex, so by using a common birthday for all horses one only needs to use the birth year, which is much simplier.