This webpage is part of a series on Dog Coat Color Genetics and was last updated on October 7, 2020 by Sheila Schmutz
Conditions Associated with Coat Color in Dogs
Black Hair Follicular Dysplasia
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Black Hair Follicular Dysplasia is a condition where the black hair does not develop properly, is brittle and breaks off easily. The hair is also not black but slate grey. The Large Munsterlander pup at left, has normal hair in its white patches but abnormal hair is its grey/black patches. HealthGene Laboratory offers the DNA test for this autosomal recessive condition in some but not all breeds (i.e. the Large Munsterlander, Newfoundland, Great Dane, Doberman Pinscher). The eyes often remain blue instead of turning to brown. Occasionally, these dogs may also be deaf. |
Blue coat color appears to be caused by more than one different mutation in the MLPH gene in the 30 breeds we studied. The commmon mutation causes dilute coat color in most dogs that are born blue or grey. The symptoms of this disorder vary widely among individuals for reasons that are not clear at this time. The symptoms seem worst in Large Munsterlanders, but Newfoundlands, Doberman Pinschers, Great Danes, Weimaraners, and Italian Greyhounds can all have symptoms. Patchy hair loss on the ears, head and along the spinal column seems to be the most common symptom. Dermatitis, wrinkled skin, allergic skin reactions, etc. all occur. Some dogs are free of symptoms early in life and then develop them later. We have collected DNA samples from blue dogs with and without symptoms to try to understand if the groups in each group had a different mutation. However some dogs with the common mutation and some without it had CDA symptoms and others did not. There may be a slightly higher chance that males may suffer more severe symptoms than females. |
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I am not a veterinarian and therefore do not prescribe or even suggest drugs. However, melatonin is an over the counter drug available in several countries. Some veterinarians have suggested this may help some dogs with BHFD or CDA, but it is not a cure. See your vet for suggestions about the dosage and optimal time for trying this.
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This disorder occurs in Rough and Smooth Collies and a few other breeds. It has several names, such as Cyclic Neutropenia and Cyclic Hematopoesis. Marshall Horwitz and co-workers at the University of Washington discovered the mutation that causes this disease. HealthGene Laboratory offers the DNA test for this autosomal recessive condition. |
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Some dogs who are born white are also deaf. These white dogs are usually those that are white from merle crosses or from crosses of "flashy" marked Boxers. Some Dalmatians are also unilaterlly or bilaterally deaf. We recently studied a group of 26 deaf Australian Shepherds who were merle with a considerable amount of white using the mutation in the SILV gene reported recently (see merle page for more details). Twenty-four were homozygous for this mutation. Apparently in other breeds that are merle without other white markings, deafness is less likely (reported by Murphy et al. at the Canine & Feline Genetics meeting in Davis, CA August, 2007). Recent DNA studies reveal that the white markings of Boxers and Dalmatians, as well as several other dogs such as Landseer Newfoundlands and Cavalier King Charles Spaniels which do not exhibit associated deafness, are caused by a mutation/s in the MITF gene. See another webpage in this series more information about white spotting. |
C.C. Little believed that albinism was rare in dogs. If one defines albinism as the complete lack of pigment in eyes, nose, pads, skin and hair then it probably is quite rare. The lack of pigment in some or all of these parts is probably less rare. The gene causing albinism in Doberman Pinchers was identified by Paige Winkler and colleagues in Michigan and is SLC45a2. Subsequently Hiruni Wijesenda identified a second mutation in this gene that caused albinism in several small long-haired breeds. However, neither mutation is present in the albino pug at the right, so there must be at least one other mutation in this gene or another gene causing albinism in dogs. See another webpage in this series more information about albinism. |
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Micropthalmia or "small eye" is a condition that occurs frequently in dogs homozygous for Merle. This condition also appears to be inherited in Akita, irrespective of their coat color. There is a gene known as MITF (microphthalmia transcription factor) that is very important in eye development and also coat color. Therefore we studied this gene extensively but thus far have failed to find a connection to either the microphthalmia of Akita. |