Some dogs lose hair only in areas of a certain coat color. In color dilution alopecia, hair thins in blue or fawn areas; in black hair follicle dysplasia, it thins only in black areas [1]. A veterinary dermatology handbook from the University of Minnesota groups both under the follicular dysplasias, breed-related problems in how the hair follicles form and grow [1].
Hair loss has many causes, and most need a different plan. The same handbook lists several conditions a vet will want to rule out first, including mites, bacterial follicle infection, ringworm and, in older dogs, an underactive thyroid [1]. So if your dog’s coat is thinning, have your vet look at it. For the wider picture, see our post on hair loss in dogs.
What these conditions are
Color dilution alopecia. This inherited condition appears in some dogs whose coat is a diluted shade: blue (a dilution of black) or fawn (a dilution of brown) [1]. Large clumps of pigment build up in and around the hairs, which seems to make the hair shafts fragile so that they break [1]. Not every dilute dog is affected: a gene study notes that hair loss and repeated skin inflammation show up in only some dogs with a diluted coat [7].
Black hair follicle dysplasia. This is a related condition in dogs with two- or three-colored coats. Pigment clumps form in the black hairs, and hair loss stays limited to the black parts of the coat [1].
Which dogs are affected
- Color dilution alopecia: the handbook lists many breeds, among them Dobermans, Dachshunds, Great Danes, Whippets, Italian Greyhounds, Yorkshire Terriers, German Shepherds, Labrador Retrievers and mixed-breed dogs with a dilute coat [1]. How often it occurs depends on the breed. The handbook gives figures of roughly 93% of blue and 73% of fawn Dobermans, while most Weimaraners do not develop it [1]. Case reports also describe it in a Miniature Pinscher and a Schnauzer [2].
- Black hair follicle dysplasia: reported in mixed-breed dogs and in breeds such as Border Collies, Bearded Collies, Papillons, Jack Russell Terriers, Dachshunds and Large Munsterlanders [1]. A case report from New Zealand describes it in a Huntaway [8].
How it is inherited
The handbook describes color dilution alopecia as an autosomal recessive trait [1]. A study of seven affected Dachshunds from five families reached the same conclusion from their family trees [3]. Gene work links coat dilution to changes in or near a gene called MLPH [7], but the handbook points out that this alone cannot explain the disease, because many dilute dogs never lose their hair [1].
For black hair follicle dysplasia, the handbook says the mode of inheritance is believed to be autosomal recessive [1], and a 1998 study of an affected litter came to the same view [5].
Autosomal recessive means a dog shows the condition when it carries two copies of the gene variant. Your vet can explain what this means for your dog.
What you may notice
Color dilution alopecia
- Signs usually begin between about 3 months and 3 years of age. Dogs with paler coats (such as grey) tend to lose hair earlier than those with darker dilute coats (such as steel blue) [1].
- It may start with repeated bumps and infection of the hair follicles along the back, or with gradually thinning hair. Over time the hair loss spreads, but only across the dilute-colored areas [1].
- One case series describes the first change as a coat that slowly becomes dry, dull and poor, with weak regrowth; small bumps can turn into blackheads, mostly on the trunk [2].
- Blackheads and scaling may appear on the bald skin [1].
- In the Dachshund study, six of the seven dogs changed shade in their first months of life, from blue and tan to a greyish or “dead leaf” and tan color [3].
Black hair follicle dysplasia
- The first sign can appear as early as about 4 weeks of age: the black hairs lose their shine. This tends to progress to near-complete hair loss in the black areas by 6 to 9 months of age [1].
- In a study of Large Munsterlander cross puppies, the affected pups had a silvery grey coat from birth and lost hair over time in the pigmented areas [4].
- In the Huntaway report, patchy hair loss stayed within the black-haired parts of the body, and the tan areas looked normal [8].
Both conditions
Dogs with color dilution alopecia are prone to superficial skin infection [1]. The Huntaway report notes that the main health effect of black hair follicle dysplasia is a tendency to plugged follicles and bacterial skin infection [8]. See our posts on pyoderma in dogs and Malassezia yeast skin infection.
How it is diagnosed
- History and pattern: hair loss that starts in a young dog and stays within the dilute (or, in the second condition, the black) parts of the coat strongly points to these conditions [1].
- Ruling out other causes: your vet will want to exclude other reasons for hair loss, such as mites, bacterial infection, ringworm and hormone problems [1].
- Looking at hairs: under the microscope, hairs from affected dogs show large clumps of pigment that distort the shaft [1]. In a study of 57 blue or fawn Dobermans, some diagnoses were confirmed by looking at plucked hairs and others by skin biopsy [6].
- Skin biopsy: a sample of skin examined in the lab shows the pigment clumps in the skin and follicles [1]. The Huntaway report adds that a biopsy helps tell the different follicular dysplasias apart, and separates them from follicle shrinkage caused by hormone disease [8].
Your vet chooses the tests for your dog.
Treatment and care
There is no cure. For color dilution alopecia, the handbook describes care as supportive: treating and preventing skin infections, and keeping bald areas out of the sun [1]. It adds that moisturizing shampoos and fatty acid supplements may help with the heavy scaling that often comes with the condition [1]. For black hair follicle dysplasia, the handbook says there is no treatment [1]. In practice, care can include:
- treating skin infections when they occur, as your vet prescribes;
- skin and coat care, such as medicated or moisturizing baths, as directed by a vet;
- protecting thin-haired skin from sun and from scrapes, as your vet advises. See our post on dry, flaky skin in dogs for scaling in general.
Because genes play a part, the handbook advises that affected dogs should not be bred [1]. Your vet will plan care for your dog. Do not use human hair-growth products or other medicines on your dog unless your vet tells you to.
Outlook
The handbook says hair does not grow back in the dilute-colored areas, and that many light-colored dogs are fully bald there by 2 to 3 years of age [1]. The main health concern is skin infection, which needs a vet [1][8]. Findings from individual studies:
- In the study of 57 blue or fawn Dobermans, 42 had the typical hair loss [6].
- A report of six cases covers dogs from 3 months to 10 years old [2].
These are figures and statements about groups of dogs in particular studies. They do not prove that a treatment caused an outcome, and they cannot predict how one dog will do. Your vet can explain what this means for your dog.
When to see your vet
See your vet if your dog has:
- thinning hair or hair loss, at any age [1];
- hair loss limited to blue, fawn or black areas of the coat [1];
- dry, dull coat, scaling, small bumps or blackheads [1][2];
- red, inflamed or infected-looking skin [1][8].
FAQ
Will the hair grow back?
For color dilution alopecia, the handbook says hair will not regrow in the dilute areas [1]. Your vet can tell you what to expect for your dog.
Is it painful or dangerous?
The hair loss itself mainly changes how the coat looks. The real problem is skin infection: affected dogs are prone to it [1][8], and infections need a vet.
Does every blue or fawn dog get it?
No. Only some dogs with a diluted coat develop hair loss [1][7], and the share varies a lot by breed [1].
Do cats get it?
This article covers dogs. Hair loss in cats has its own list of causes. See our post on hair loss in cats.
The bottom line
Color dilution alopecia causes hair loss in blue or fawn areas, and black hair follicle dysplasia causes hair loss in black areas, in dogs with these coat colors [1]. Neither can be cured; care aims to prevent skin infections and protect the skin [1]. Because many conditions cause hair loss, have your vet check a thinning coat.
This article is for general information and does not replace a visit to your veterinarian. If your dog is losing hair, contact your vet.
Sources
- Torres SMF. 1.11 Canine Follicular Dysplasias. Small and Large Animal Dermatology Handbook, Vol. 2. University of Minnesota, 2025. CC BY 4.0. https://open.lib.umn.edu/animaldermatology2/chapter/canine-follicular-dysplasias/
- Kim JH, Kang KI, Sohn HJ, et al. Color-dilution alopecia in dogs. J Vet Sci. 2005;6(3):259-261. https://pubmed.ncbi.nlm.nih.gov/16131833/
- Beco L, Fontaine J, Gross TL, Charlier G. Colour dilution alopecia in seven Dachshunds. A clinical study and the hereditary, microscopical and ultrastructural aspect of the disease. Vet Dermatol. 1996;7(2):91-97. https://pubmed.ncbi.nlm.nih.gov/34645045/
- von Bomhard W, Mauldin EA, Schmutz SM, et al. Black hair follicular dysplasia in Large Münsterländer dogs: clinical, histological and ultrastructural features. Vet Dermatol. 2006;17(3):182-188. https://pubmed.ncbi.nlm.nih.gov/16674733/
- Schmutz SM, Moker JS, Clark EG, Shewfelt R. Black hair follicular dysplasia, an autosomal recessive condition in dogs. Can Vet J. 1998;39(10):644-646. https://pubmed.ncbi.nlm.nih.gov/9789677/
- Miller WH Jr. Colour Dilution Alopecia in Doberman Pinschers with Blue or Fawn Coat Colours: A Study on the Incidence and Histopathology of this Disorder. Vet Dermatol. 1990;1(3):113-122. https://pubmed.ncbi.nlm.nih.gov/34644836/
- Philipp U, Hamann H, Mecklenburg L, et al. Polymorphisms within the canine MLPH gene are associated with dilute coat color in dogs. BMC Genet. 2005;6:34. CC BY. https://pubmed.ncbi.nlm.nih.gov/15960853/
- Munday JS, French AF, McKerchar GR. Black-hair follicular dysplasia in a New Zealand Huntaway Dog. N Z Vet J. 2009;57(3):170-172. https://pubmed.ncbi.nlm.nih.gov/19521467/