The Mustang is a feral horse breed from the Western United States, descended from equines brought to the Americas by Spanish explorers. Shaped by the rugged terrains of the western frontier, the Mustang now stands as an iconic breed, embodying the resilience required to survive its demanding environment.

Free-roaming Mustangs on public lands are now managed by the Bureau of Land Management’s Wild Horse and Burro Program. But these horses are also adopted and bred in private domestic homes.

There are several strains of Mustangs, including the Kiger Mustang and the Spanish Mustang, which retains the bloodlines of the original horses brought by Spanish settlers.

While controversy surrounds population control methods used in free-roaming herds, Mustangs are still a cherished symbol of the American West. Many adopted Mustangs go on to successful riding careers with appropriate care and training.

This breed profile will discuss the history, characteristics, health problems, and nutritional needs of the Mustang breed. Keep reading to learn more about feeding and caring for Mustang horses.

Mustang Horse History

The history of the American Mustang traces back over five centuries to the first Spanish conquistadors that travelled to the Americas.

Origin

Colonial Spanish Horses are the founding ancestors of the Mustang breed. Early horses were left behind or released from Spanish missions and settlements. Feral herds established themselves and eventually spread throughout the Wild West. [1]

Over time, many horse breeds influenced the development of the modern Mustang. Several breeding populations became genetically isolated in different geographic locations, resulting in various strains of Mustangs.

Some feral herds have distinct types that suggest the introduction of Thoroughbred or Quarter horse blood. A few have draft horse characteristics, but many still resemble the light-riding horse type of the original Spanish horses.

Mitochondrial DNA studies confirm the Iberian origin of the American Mustang, linking the breed to the Iberian Peninsula in Spain. Researchers have identified a high frequency of Iberian haplotypes (DNA sequences) in several strains of Mustangs. [2]

Historic Use

During his 1519 expedition, Hernán Cortés introduced the first Spanish horses to what is now mainland Mexico. That expedition is now infamous for causing the fall of the Aztec Empire. [3]

In the late 16th century, Juan de Onate brought 75 Spanish horses on his expedition across the Rio Grande. After establishing the province of Santa Fe de Nuevo México, the region’s horse population swiftly grew from this initial herd. [3]

Sante Fe became a significant trading center in the 17th century. Horses dispersed from Mexico throughout the American West. Some animals were traded to other settlers or indigenous people, while others wandered off to form feral herds. [4]

American settlers encountered large herds of Mustangs ranging from the Pacific Northwest to the Great Plains by the early 19th century. Round-ups captured thousands of these horses for use in the Spanish-American War and World War I.

Most remaining feral herds lived west of the Continental Divide on public lands. The United States Grazing Service began in 1934 to manage livestock grazing on these public lands until the Bureau of Land Management (BLM) was formed in 1946.

The BLM initially sought to remove feral horses from public lands. Controversy over capture methods led to the first horse protection laws in the 1950s. The Wild and Free-Roaming Horses and Burros Act of 1971 further increased the protection of American Mustangs. [5]

Breed Registry

The Bureau of Land Management monitors Mustang populations in established Herd Management Areas to prevent overpopulation. The bureau manages the population with off-range corrals and purchase centers that allow potential owners to adopt Mustangs. [5]

Several organizations, such as the Mustang Heritage Foundation, are dedicated to helping Mustangs find good homes and reducing the number of horses kept in long-term holding corrals.

Some breed registries also promote the preservation of the original Mustang. For example, the Spanish Mustang Registry only registers the offspring of registered Spanish Mustang parents.

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Breed Characteristics

Modern Mustangs exhibit diverse body types, influenced by the ancestral lineage of horses from various geographic locations. But most Mustangs share characteristics that allow them to survive in the wild and thrive in new homes with appropriate training.

Conformation

Most Mustangs are small horses with a height between 14 and 15 hands tall. Mustangs found in herd management areas overseen by the BLM generally have a light-riding horse type. Some still resemble the original Spanish Mustang, while others have less Spanish blood.

Their heads have flat or slightly convex profiles and broad foreheads that taper to a fine muzzle. Eyes are often set slightly higher on the face. A defined