Color Mutations in Dobermans
Color Dilution Alopecia Genetic Skin Condition in Dogs
History
Color dilution alopecia, or color mutant alopecia, was originally knows as blue balding syndrome, blue doberman syndrome, congenital alopecia, and blue dog diseaseRevernces to doberman pinschers and blue hair coats originated because the condition is common in blue dogs.
This disease can be seen in a variety of canine breeds including doberman pinschers, Irish setters, dachshunds, chow chows, standard poodles, great danes,Italian greyhounds, and whippets.
This disease can be seen in a variety of canine breeds including doberman pinschers, Irish setters, dachshunds, chow chows, standard poodles, great danes,Italian greyhounds, and whippets.
What is it?
This disease can be present in many breeds of dogs. It is most common in "dilute-colored" dogs such as fawn (dilution of a normally red or brown coat) and blue (dilution of the normal black and tan coat) colored dobermans. It is a skin disease with delayed onset.
The disease may not appear until the dog is 4-18 months of age and may be delayed as long as 3-6 years. There is no noticed sex predilection. This condition is progressive with a gradual onset of dry, dull, and poor hair coat.
The disease may not appear until the dog is 4-18 months of age and may be delayed as long as 3-6 years. There is no noticed sex predilection. This condition is progressive with a gradual onset of dry, dull, and poor hair coat.
Implications
According to Perego, et.al. (2009) it is present in blue and fawn colored doberman pinschers with an incidence rate of 57.9% and 89.5% respectively.
Several years after the onset of color dilution alopecia, hypotrichosis (abnormal hair patterns) begins and may progress until alopecia extends along the entire body sparing the head, tail, and limbs and any non-diluted coat areas. The skin in the affected area is usually scaly and follicular papules may develop and may progress to recurrent bacterial folliculitis. Abnormal clumps of melanin are often present in the epidermis, dermis, and epithelia of hair follicles. Aside from these coat and skin conditions, dogs with color dilution alopecia appear to be in good general health.
Several years after the onset of color dilution alopecia, hypotrichosis (abnormal hair patterns) begins and may progress until alopecia extends along the entire body sparing the head, tail, and limbs and any non-diluted coat areas. The skin in the affected area is usually scaly and follicular papules may develop and may progress to recurrent bacterial folliculitis. Abnormal clumps of melanin are often present in the epidermis, dermis, and epithelia of hair follicles. Aside from these coat and skin conditions, dogs with color dilution alopecia appear to be in good general health.
Transmission
While the mechanisms of alopecia are not well understood, color dilution alopecia is based on autosomal recessive gene transmission. The dilution gene called -d, especially the allele called -d1, may play an important role in transmission of this disease.
Genotypes and Phenotypes
This disorder, being carried on an autosomal recessive gene, the genotypes are simple. If the affected allele is represented by "d1" and the dominant, unaffected allele is represented by "D", the the possible genotypes are
Not all dogs with the dilution genes develop alopecia or other coat abnormalities. There are multiple levels of abnormalities such as:
- DD - unaffected
- Dd1 - also unaffected, but a carrier for the gene
- and d1d1 - affected by color dilution alopecia
As such, athe only way to have offspring which express color dilution alopecia is to breed two parents who are both affected by the disorder. If a dog with the genotype DD (unaffected) and a dog with the genotype Dd1, or two Dd1 dogs, were bred, the offspring would potentially be carriers of the genes that cause this disorder.
Not all dogs with the dilution genes develop alopecia or other coat abnormalities. There are multiple levels of abnormalities such as:
- abnormal keratinization
- abnormalities of pigment transfer
- defects in melanization
- abnormal storage of undegraded melanosomes
- defects of hair follicle function.
Eradication
Currently, there is no specific or curative therapy for color dilution alopecia. However, frequent baths given once or twice per week with keratomodulating or antiseborrhoeic agents (i.e. salicylic acid or benzoyl peroxide) can reduce occurrence of bacterial infections and mitigate some other symptoms of this condition.
While no active measures are being taken to eradicate this genetic condition, the vital prognosis is good and it is recommended not to breed individuals with this condition in order to prevent transmission.
While no active measures are being taken to eradicate this genetic condition, the vital prognosis is good and it is recommended not to breed individuals with this condition in order to prevent transmission.
Opinion
The transmission and genetics of color dilution alopecia is not well understood. However, it is tied to animals with dilute colored coats indicating that it is likely a result of a mutation that occurred when breeding for lighter, "dilute" colored coats. Coat color in dobermans, and most dogs, is purely aesthetic. This means that this disorder, which causes an uncomfortable skin condition in dogs, is a result of breeding for peoples' aesthetic preferences. While this condition is not life-threatening and appears to have minimal to no effect on overall health of an affected individual, it can be said that quality of life for affected individuals is reduced as a result of uncomfortable skin irritation, bacterial infections, and the loss of fur which is important for temperature regulation and protection from sunburn. Unfortunately, this disease is late onset meaning that breeders may not know their dogs have this condition until they have been bred, especially in individuals who do not show symptoms until 3-6 years of age. Also, at the moment, this disease cannot be diagnosed until symptoms begin to show. Should efforts be put to finding a way to diagnose this disease at birth in order to prevent breeding of affected individuals despite the lack of health problems outside of skin infections and displeasing aesthetics?
References
1. "Color Dilution Alopecia." Dermatology for Animals. N.p., n.d. Web. 28 Apr. 2016.
2. "Derm Digest Newsletter." Animal Dermatology Clinics. N.p., August 2010. Web. 28 Apr. 2016.
3. Kim, Jae-Hoon, Kyung-Il Kang, Hyun-Joo Sohn, Gye-Hyeong Woo, Young-Hwa Jean, and Eui-Kyung Hwang. "Color-dilution Alopecia in Dogs." Journal of Veterinary Science 6.3 (2005): 259-61. Web. 28 Apr. 2016.
4. Perego, Roberta, Daniela Proverbio, Paola Roccabianca, and Eva Spada. "Color Dilution Alopecia in a Blue Doberman Pinscher Crossbreed." The Canadian Veterinary Journal 50.5 (2009): 511-514. The Canadian Veterinary Journal. Canadian Veterinary Medical Association. Web. 28 Apr. 2016.
5. Phillip, U., H. Hamann, L. Mecklenburg, S. Nishino, E. Mignot, A. R. Gunzel-Apel, S. M. Schmutz, and T. Leeb. "Polymorphisms within the Canine MLPH Gene Are Associated with Dilute Coat Color in Dogs." BMC Genetics 6.34, 2005 Web. 28 Apr. 2016.
2. "Derm Digest Newsletter." Animal Dermatology Clinics. N.p., August 2010. Web. 28 Apr. 2016.
3. Kim, Jae-Hoon, Kyung-Il Kang, Hyun-Joo Sohn, Gye-Hyeong Woo, Young-Hwa Jean, and Eui-Kyung Hwang. "Color-dilution Alopecia in Dogs." Journal of Veterinary Science 6.3 (2005): 259-61. Web. 28 Apr. 2016.
4. Perego, Roberta, Daniela Proverbio, Paola Roccabianca, and Eva Spada. "Color Dilution Alopecia in a Blue Doberman Pinscher Crossbreed." The Canadian Veterinary Journal 50.5 (2009): 511-514. The Canadian Veterinary Journal. Canadian Veterinary Medical Association. Web. 28 Apr. 2016.
5. Phillip, U., H. Hamann, L. Mecklenburg, S. Nishino, E. Mignot, A. R. Gunzel-Apel, S. M. Schmutz, and T. Leeb. "Polymorphisms within the Canine MLPH Gene Are Associated with Dilute Coat Color in Dogs." BMC Genetics 6.34, 2005 Web. 28 Apr. 2016.
Picture References
http://www.dobermantalk.com/doberman-health/65878-skin.html
Kim, Jae-Hoon, Kyung-Il Kang, Hyun-Joo Sohn, Gye-Hyeong Woo, Young-Hwa Jean, and Eui-Kyung Hwang. "Color-dilution Alopecia in Dogs." Journal of Veterinary Science 6.3 (2005): 259-61. Web. 28 Apr. 2016.
http://www.dobermancanada.com/pick-a-color/
http://www.animaldermatology.com/newsletter/429/Derm-Digest-august-2010
Kim, Jae-Hoon, Kyung-Il Kang, Hyun-Joo Sohn, Gye-Hyeong Woo, Young-Hwa Jean, and Eui-Kyung Hwang. "Color-dilution Alopecia in Dogs." Journal of Veterinary Science 6.3 (2005): 259-61. Web. 28 Apr. 2016.
http://www.dobermancanada.com/pick-a-color/
http://www.animaldermatology.com/newsletter/429/Derm-Digest-august-2010