Understanding Dog Colors and Coat Patterns
Domestic dogs come clothed in hundreds of color, pattern and coat varieties, a pretty amazing feat for a species that developed from a rather drab-looking ancestral wolf. This ancient animal had a medium length brown to tan coat, just perfect for blending into his surroundings.
After dogs began their association with humans, however, they were transported into other areas and climates, and Mother Nature did the rest - spontaneous genetic mutation brought us the myriad colors, patterns and coat varieties we enjoy today. Because of these mutations, our canine friends come in hundreds of color and pattern combinations. Humans also played a role in coloring outside the bloodlines through selective breeding.
While all of these choices are great for the dog lover who likes variety, they also can be confusing. What does a “merle” dog look like? What's the difference between brindle and roan? And just what the heck is a particolor? Read on for a short course in dog color and pattern.
Understanding a Dog's Hair Type and Length
You may not realize it but there are several different types of hair that work together to create your dog's coat. The type of hair the dog has depends somewhat on his country of origin (tropical, arctic), original purpose (hunter, protector) and genetics.
Type of Hair.
Most breeds of dog have three different hair types: tactile hair, an outer coat and an undercoat.
Length of Hair.
The length of the hair is often connected to the area in which the dog was originally developed.
Types of Hair Coat.
In addition to a variety of coat lengths and hair types, there are also many different types of coat. Some common types include:
Understanding a Dog's Hair Color
A dog's color depends upon the presence of pigmentation in the epidermis. For dogs, only two pigments exist: black-brown and yellow-red. All dogs, no matter what color they are on the outside, are genetically either black-brown or yellow-red. All other colors result from other genetic factors or modifiers acting on these two pigments. Pigments are produced in cells called melanocytes, and the distribution and number of these cells are determined by the dog's genetic makeup. These cells pass the pigment onto the dog's hair, skin and eyes, and create the pattern and color. In addition, the melanocytes may not produce pigment during all stages of hair development, resulting in banding, agouti, ticking, etc.
Three specific genes are essential to the dog's colorful exterior: pigment, color and density. The pigment gene determines the amount of pigment that's distributed over the dog's body. The color gene determines the intensity of the dog's color. The density gene determines the density of the pigmentation; the more densely packed the pigment, the darker the color will be. For example, in order to appear black, the dog must possess three genes: B for black pigmentation, D for dense coloration, and C for full color. These are all dominant genes. However, these genes have corresponding recessive mutations that can change the dog's appearance.
Dog Hair Mutations
Researchers have identified several mutations that occurred many years ago, when canines had only recently become so-called domestic animals. These mutations are not the only ones that affect color and pattern, but they are essential for the myriad color, pattern, and coat varieties we see in dogs today. They are:
A system of internationally recognized symbols was established to make it easier to understand the color genes and relationships to one another. Capital letters indicate dominant genes while lower case letters represent recessive genes.
Today's Dog Hair Colors and Patterns
The mixing and matching of genes gives us the many color and pattern combinations we see in dogs today. In addition to genes, the color of the dog often is related to the dog's purpose in life. Dogs used to protect sheep are often selectively bred to be white in order to blend into the flock. Dogs bred to herd sheep are selectively bred not to be white. This allows the rancher to identify the dog easily among the sheep and snow.
Solid. In dogs, a solid-colored dog is any dog that is one solid color without recognizable stripes, spots, ticking, patches of white or shading. In some breeds, a splash of white is acceptable.
Common solid colors are:
Patterns. There are many different coat patterns that are produced by a combination of colors. Some common patterns include:
Particolor. Depending upon the breed, a particolor is a dog that has patches of two or more colors, or that has any color or pattern combined with white. Some particolor patterns include: