Varnish roan describes a horse

Horse

The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

 with coloration similar to roan

Roan (horse)

Roan is a horse coat color pattern characterized by an even mixture of colored and white hairs on the body, while the head and "points"—lower legs, mane and tail—are more solid-colored. The roan pattern is dominantly-inherited, and is found in many horse breeds...

, but with some changes in color over the years, though not to the extreme of a gray

Gray (horse)

Gray or grey is a coat color of horses characterized by progressive silvering of the colored hairs of the coat. Most gray horses have black skin and dark eyes; unlike many depigmentation genes, gray does not affect skin or eye color Their adult hair coat is white, dappled, or white intermingled...

. This type of roaning only occurs in conjunction with the Leopard complex

Leopard complex

The leopard complex is a group of genetically-related coat patterns in horses. These patterns range from progressive increases in interspersed white hair similar to graying or roan to distinctive, Dalmatian-like leopard spots on a white coat. Secondary characteristics associated with the leopard...

. Varnish roans are born with a dark base coat color, usually with some spotting. As the horse ages, white hairs increase over most of the body, and many spotted markings blur or fade. The varnish roan pattern often appears to spread from the white of any original markings. This color pattern is best known in the Appaloosa

Appaloosa

The Appaloosa is a horse breed best known for its colorful leopard-spotted coat pattern. There is a wide range of body types within the breed, stemming from the influence of multiple breeds of horses throughout its history. Each horse's color pattern is genetically the result of various spotting...

 breed of horse.

Varnish roan is not a result of the roan or the Gray

Gray (horse)

Gray or grey is a coat color of horses characterized by progressive silvering of the colored hairs of the coat. Most gray horses have black skin and dark eyes; unlike many depigmentation genes, gray does not affect skin or eye color Their adult hair coat is white, dappled, or white intermingled...

 gene, but part of the Leopard complex

Leopard complex

The leopard complex is a group of genetically-related coat patterns in horses. These patterns range from progressive increases in interspersed white hair similar to graying or roan to distinctive, Dalmatian-like leopard spots on a white coat. Secondary characteristics associated with the leopard...

. A horse may have varnish roan coloration in conjunction with other leopard patterns.

Characteristics

By adulthood, the Varnish Roan usually has a base coat of intermingled dark and white hairs, though more white hairs than dark, with mottled skin, color mainly on the cheeks of the face, and around the knees. The darker areas remain at bony points (on the face, usually in a distinct V on the bridge of the nose; on the cheeks, point of shoulder, elbows, knees, point of hips, hock) and it can be seasonal as well. Although classic roans are roan from birth, varnish roans are often born with spots and "roan out" as they age. A horse's appearance can change almost completely, although the original markings are usually visible.

The pattern is not completely stable. The horse is born another color (usually another leopard pattern), and the Varnish pattern gradually overtakes it by adulthood. After the horse is mature, the coat color may lighten slightly when the horse has a long winter coat, and darken slightly in the summer when the winter coat sheds out. However, unlike the gray gene, the color does not get progressively lighter every year for the life of the horse, though it may look a bit different from year to year while the horse is young.

Varnish vs true roan

The varnish roan is not a true roan, it is actually one of the leopard complex

Leopard complex

The leopard complex is a group of genetically-related coat patterns in horses. These patterns range from progressive increases in interspersed white hair similar to graying or roan to distinctive, Dalmatian-like leopard spots on a white coat. Secondary characteristics associated with the leopard...

 coat patterns associated with Appaloosa

Appaloosa

The Appaloosa is a horse breed best known for its colorful leopard-spotted coat pattern. There is a wide range of body types within the breed, stemming from the influence of multiple breeds of horses throughout its history. Each horse's color pattern is genetically the result of various spotting...

, Knabstrupper, Noriker horse

Noriker horse

The Noriker horse, also called the Norico-Pinzgauer and historically known as the Pinzgauer horse, is a moderately heavy Austrian draught horse breed. The Noriker is considered indigenous to the central Alpine region of Europe, and is believed to have originated around the highest mountain of...

 and related breeds. Varnish roans are not true roans and can be distinguished from true roans by the following:

• Leopard complex
  Leopard complex
  The leopard complex is a group of genetically-related coat patterns in horses. These patterns range from progressive increases in interspersed white hair similar to graying or roan to distinctive, Dalmatian-like leopard spots on a white coat. Secondary characteristics associated with the leopard...
  
   characteristics. Varnish roans, like all horses with the Lp gene, have mottled skin, striped hooves, and white sclera.
• Varnish roans change color seasonally, often becoming less spotted as they age, and often having their coats become lighter when a winter coat grows in, though they do not progressively lighten in the manner of a gray horse
  Gray (horse)
  Gray or grey is a coat color of horses characterized by progressive silvering of the colored hairs of the coat. Most gray horses have black skin and dark eyes; unlike many depigmentation genes, gray does not affect skin or eye color Their adult hair coat is white, dappled, or white intermingled...
  
  .
• Bony areas retain their pigment longer. These areas include the bridge of the nose and cheekbones, ears, points of shoulder and stifle, as well as the legs.
• Appaloosa
  Appaloosa
  The Appaloosa is a horse breed best known for its colorful leopard-spotted coat pattern. There is a wide range of body types within the breed, stemming from the influence of multiple breeds of horses throughout its history. Each horse's color pattern is genetically the result of various spotting...
  
   characteristic parentage.

Genetics

Varnish roan is thought to occur due a single, simple dominant gene

Dominance relationship

Dominance in genetics is a relationship between two variant forms of a single gene, in which one allele masks the effect of the other in influencing some trait. In the simplest case, if a gene exists in two allelic forms , three combinations of alleles are possible: AA, AB, and BB...

 on equine chromosome

Chromosome

A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

 1 (ECA1). It also appears that specific white patterning genes produce the assorted blanket, leopard, and snowflake coat patterns. Without these white patterning factors, horses with one or two copies of the dominant Lp gene are "varnish roans." Varnish roans can be considered to have many, many very small leopard spots that reflect the mottling of the underlying skin.

A horse may be varnish roan as well as true roan and gray, but such combinations are extremely uncommon. The breeding of grays

Gray (horse)

Gray or grey is a coat color of horses characterized by progressive silvering of the colored hairs of the coat. Most gray horses have black skin and dark eyes; unlike many depigmentation genes, gray does not affect skin or eye color Their adult hair coat is white, dappled, or white intermingled...

 is discouraged by the Appaloosa Horse Club

Appaloosa Horse Club

The Appaloosa Horse Club, located in Moscow, Idaho is dedicated to preserving and promoting the Appaloosa breed. The state of Idaho adopted the Appaloosa as its state horse in 1975. More than 630,000 Appaloosas have been registered with the Appaloosa Horse Club since its founding in 1938...

 and not allowed by Knabstrupper breed registry.