Whether you love them or are afraid of them, everyone knows what a chihuahua looks like. Possibly best known as the smallest dog with the biggest bark, chihuahuas are a unique breed of dog. However, they can be made even more unique by a genetic mutation. No, they don’t morph into ninjas, but they do become a unique spotted color, not natural to their original blood line. They are often referred to as merle.
1. The Merle Chihuahua is described as having a coat with unusual patches of color. These patches are the result of a genetic mutation found in some blood lines.
Also called dapple, the patches can show up on any coat color. Often, they are gray or white with black splotches. They can also have blue eyes and pink pigmentation to their skin. This is unique as according to the AKC as chihuahuas mostly come in black, black and tan, fawn, chocolate, cream, and red coat colors with dark brown eyes and darker skin pigments. Merle coats are not listed under the breed’s standard coloring. In fact, a Merle Chihuahua is among the rarest of coats found, along with lavender, brindle, and pure white.
2. A pure white or light colored chihuahua can also be called a ghost or ghost merle.
This is because this pigmentation often occurs when the mutation of the merle gene is there, but just does not show up. It is important to keep this in mind when breeding a light colored chihuahua as they could pass this dominant gene onto their offspring.
3. The American Kennel Club lists the Merle chihuahua as having a rounded head with erect ears and expressive eyes.
Not only do their coats come in several varieties, but they can also be either long or short. The colors are listed above but there are also a few standard rare markings such as black brindle, black mask, and even merle. The chihuahua should stand no more than 8 inches tall and weigh no more than 6 lbs. They can live up to 16 years of age. Chihuahuas shed seasonally and therefore only require occasional grooming. Because of their Napoleon syndrome, they do best with older children and adults. Merle chihuahuas often have all the breed standards listed and can come in both red and blue varieties of merle.
4. The merle phenotype is inherited as an autosomal, incompletely dominant trait.
Put simply, this means that a parent chihuahua could not show the mutation physically but still carry the gene. This means they can produce merle offspring and even double-merle offspring.
5. Although recognized by the AKC in the past, the Merle Chihuahua is not considered purebred by definition.
This is because it is thought the merle gene does not occur naturally in chihuahuas. However, a merle chihuahua that meets all other breed standards and was not produced by a merle parent, can be considered for AKC recognition.
6. It is important to know whether the breeding pair of chihuahuas carries the merle gene or not.
This is because if two chihuahuas that both carry the merle gene procreate, they produce double-merle offspring. While a double-merle may sound like a beautiful creation, it can have ugly outcomes. The dilute pigmentation of a singular merle chihuahua can cause skin sensitivities, hearing issues, and even eye issues. This is why the offspring of a merle chihuahua are not recognized by the AKC any longer. Double-merle chihuahuas often exhibit more extreme heath issues such as severe deafness, increased eye abnormalities, skeletal, cardiac and reproductive defects.
7. There are DNA tests available through a licensed veterinarian to see if a dog, like the chihuahua, carries the merle gene mutation.
Using a simple blood sample or cheek swab, the licensed veterinarian can order the test through IDEXX, a “global leader in veterinary diagnostics, software, and water microbiology testing.” The test can take up to a week for return but is fairly simple to execute.
8. Knowing the complications that come with the merle gene mutation, it can be said that it is unethical to purposely produce merle chihuahuas.
The health issues that they can face were enough reason for the AKC to stop the registration of them in 2009. It is also why such organizations as The Chihuahua Club of America has a Merle Statement:
“Due to the amount of colors and patterns occurring in the Chihuahua breed the ethical breeding of the merle pattern can be much more difficult than in other breeds who limit the allowed colors and patterns. The purpose of these guidelines is to give beginning tools to avoid or limit the production of hidden merles.”
The guidelines cover breeding double merles, breeding cryptic (or ghost) merles, breeding piebalds and merles, registration of merles, and genetic testing. This makes it easier for breeders to ensure a healthier, more ethical line.
9. How much are merle chihuahuas?
Again, the merle genetic mutation, although dominant, is still rare among the chihuahua bloodline. But because this is not a registerable color, a merle chihuahua can cost either the same or just a bit more than a standard colored chihuahua. The mean cost for a purebred chihuahua puppy is around $1500. Of course, this can change due to breeder experience, championship bloodlines, and other factors.
If you want to buy one or just admire one from afar, it is almost impossible to argue about the beauty of the merle chihuahua. With beauty comes pain, as they say. So the next time you see one, maybe you will question how it got here and whether or not the mutation should stay.