* Total population: This is the most obvious factor, but it doesn't tell the whole story.
* Geographic distribution: A breed might be rare globally but common in a specific region.
* Conservation status: Some breeds are considered endangered, but others might be threatened or vulnerable.
However, some contenders for the title of rarest horse breed include:
* Akhal-Teke (Turkmenistan): Known for its metallic coat and endurance, this breed has a population of around 3,500 worldwide.
* Kladruber (Czech Republic): A majestic breed with a distinctive white coat, it has a population of around 2,000.
* Friesian (Netherlands): With its striking black coat and flowing mane, this breed has a population of around 2,500.
* American Paint Horse: While the breed itself is popular, some color variations, particularly the "tovero" pattern, are very rare.
* Exmoor Pony (England): This ancient breed of pony is critically endangered, with a population of around 250.
Other potentially rare breeds:
* Marwari (India): Known for its inward-turning ears.
* Bashkir Curly (Russia): A unique breed with curly hair.
* Mustang (United States): While feral mustangs are plentiful, purebred descendants are rare.
It's important to note that these are just a few examples, and other breeds may be considered rare depending on the criteria used.
If you're interested in learning more about a specific breed, I recommend contacting a breed association or reputable equine organization.