Follicular dysplasia is a genetic disease of

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...

s causing

alopecia Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarring ...

, also called hair loss. It is caused by

hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction betwee ...

s that are misfunctioning due to structural abnormality. There are several types, some affecting only certain breeds. Diagnosis is achieved through a

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, an interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves the extraction of sampling (medicine), sample ...

, and treatment is rarely successful. Certain breeds, such as the

Mexican Hairless Dog The Xoloitzcuintle (or Xoloitzquintle, Xoloitzcuintli, or Xolo) is one of several breeds of hairless dog. It is found in standard, intermediate, and miniature sizes. The Xolo also comes in a coated variety, totally covered in fur. Coated and hair ...

and

Chinese Crested Dog The Chinese Crested Dog is a hairless breed of dog. Like most hairless dog breeds, the Chinese Crested Dog comes in two varieties, without hair and with hair, which can be born in the same litter: the hairless and the powderpuff. Description T ...

, are bred specifically for alopecia.

Structural follicular dysplasia

Structural follicular dysplasia varies by breed but all involve weakened hairs that break easily. Hair loss is originally seen in areas of repeated grooming or trauma, for instance the neck because of contact with a collar. Hair regrowth may occur, but the hair will be even weaker and the pattern will repeat. The dogs are affected between the ages of two and four years, and it is most commonly seen on the back towards the tail. Progression of the hair loss to cover the trunk can occur.

Commonly affected breeds

Irish Water Spaniel The Irish Water Spaniel (Irish: ''An Spáinnéar Uisce'') is a breed of dog that is the tallest of the spaniels. Description Appearance The Irish Water Spaniel is a sturdy, cobby dog native to Ireland. The coat, consisting of dense curls, ...

Portuguese Water Dog The Portuguese Water Dog originated from the Algarve, Algarve region of Portugal. From there the breed expanded to all around Portugal's coast, where they were taught to herd fish into fishermen's nets, retrieve lost tackle or broken nets, an ...

Curly Coated Retriever The Curly-coated Retriever (not always hyphenated, and often called the Curly for short) is a breed of dog originally bred in England for upland bird and waterfowl hunting. It is the tallest of the retrievers and is easily distinguishable by ...

Atrophic follicular dysplasia / pattern baldness

In some breeds hair follicles in certain parts of the body become progressively miniaturized, analogous to what occurs in male pattern baldness in humans. It is most commonly seen in

Dachshund The dachshund ( or ; German: 'badger dog'), also known as the wiener dog or sausage dog, badger dog, doxen and doxie, is a short-legged, long-bodied, hound-type dog breed. The dog may be smooth-haired, wire-haired, or long-haired, with varie ...

Miniature Pinscher The Miniature Pinscher, also known as the Zwergpinscher, Mini Pin and Min Pin for short, is a small breed of dog of the pinscher type originating in Germany. While the breed's visual similarities to the Toy Manchester Terrier, which somewhat resem ...

s, and Chihuahuas. Affected areas become progressively more alopecic. The pattern of hairlessness that results is somewhat breed-dependent and sex dependent. In short-coated toy and miniature dogs, ventral neck, ventral chest, ventral abdomen and inner thighs are affected. In males, the pinnae (ear flaps) are affected. In

Greyhound The English Greyhound, or simply the Greyhound, is a dog breed, breed of dog, a sighthound which has been bred for coursing, greyhound racing and hunting. Some are kept as show dogs or pets. Greyhounds are defined as a tall, muscular, smooth-c ...

s, the thighs are affected as well as the ventral chest and abdomen.

Cyclic follicular dysplasia

Cyclic follicular dysplasia is also known as seasonal alopecia. It causes bilateral hair loss and

hyperpigmentation Hyperpigmentation, also known as the dark spots or circles on the skin, is the darkening of an area of Human skin, skin or nail (anatomy), nails caused by increased melanin. Causes Hyperpigmentation can be caused by sun damage, inflammation, or ...

of the flanks. The disease usually starts in the late fall or early spring, and can regrow in about six months, although the hair may be different in color or texture. Treatment with

melatonin Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cow ...

may result in hair regrowth sooner, so it is thought that the amount of daylight influences this condition. The dogs are affected between the ages of two and four years.

Commonly affected breeds

Airedale Terrier The Airedale Terrier (often shortened to "Airedale"), also called Bingley Terrier and Waterside Terrier, is a dog breed of the terrier type that originated in the valley (''dale'') of the River Aire, in the West Riding of Yorkshire, England. It ...

Bulldog The Bulldog is a British breed of dog of mastiff type. It may also be known as the English Bulldog or British Bulldog. It is a stocky, muscular dog of medium size, with a large head, thick folds of skin around the face and shoulders and a rel ...

Rhodesian Ridgeback The Rhodesian Ridgeback is a large dog breed originally bred in Southern Africa. The original breed standard was drafted by F.R. Barnes, in Bulawayo, Southern Rhodesia (now Zimbabwe), in 1922, and approved by the Kennel Union of Southern Africa, ...

Staffordshire Bull Terrier The Staffordshire Bull Terrier, also called the Staffy or Stafford, is a purebred dog of small to medium size in the terrier group that originated in the northern parts of Birmingham and in the Black Country of Staffordshire, for which it ...

Wirehaired Pointing Griffon The Wirehaired Pointing Griffon (also called the Korthals Griffon and the Griffon d'arrêt à poil dur Korthals in France and Quebec) is a breed of dog used in hunting as a gundog. It is sometimes considered to be Dutch in ancestry, due to ...

Boxer Boxer most commonly refers to: *Boxer (boxing), a competitor in the sport of boxing * Boxer (dog), a breed of dog Boxer or boxers may also refer to: Animal kingdom * Boxer crab * Boxer shrimp, a small group of decapod crustaceans * Boxer snipe ee ...

Affenpinscher The Affenpinscher () is a German list of dog breeds, breed of small toy dog of Pinscher type. Originally developed as a Ratter (dog), mouser, the Affenpinscher is now commonly found as a Companion dog, companion worldwide. History The word '' ...

Follicular lipidosis

Follicular lipidosis is a type of follicular dysplasia found in the

Rottweiler The Rottweiler (, , ) is a breed of domestic dog, regarded as medium-to-large or large. The dogs were known in German as , meaning Rottweil butchers' dogs, because their main use was to herd livestock and pull carts laden with butchered mea ...

and other red point dogs. It usually occurs before the age of nine months and involves loss of some of the mahogany or red hair of the face and feet. It is caused by

lipid Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing ...

invasion of the hair follicle cells.

Color dilution alopecia

Color dilution alopecia is caused by a

dilution gene A dilution gene is any one of a number of genes that act to create a lighter coat color in living creatures. There are many examples of such genes: General Diluted coat colors have melanocytes, but vary from darker colors due to the concentration ...

affecting

eumelanin Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are ...

. It is an inherited type of follicular dysplasia. It most commonly affects dogs with blue or fawn coats, which are dilutions of black and brown, respectively Dilution is caused by irregularities in

melanin Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are ...

transfer and storage.

Melanosome A melanosome is an organelle found in animal cells and is the site for synthesis, storage and transport of melanin, the most common light-absorbing pigment found in the animal kingdom. Melanosomes are responsible for color and photoprotectio ...

s may clump within

melanocyte Melanocytes are melanin-producing neural-crest, neural crest-derived cell (biology), cells located in the bottom layer (the stratum basale) of the skin's epidermis (skin), epidermis, the middle layer of the eye (the uvea), the inner ear, vagina ...

s of the skin and hair follicles, causing the hair shafts to easily fracture. Signs of color dilution alopecia include hair loss and recurrent skin infection on the back. It can involve the whole body. The condition starts between the ages of six months and two years, depending on the degree of dilution. Early hair loss occurs due to hair breakage, making it similar to structural follicular alopecia. It is important to treat the skin infections, and

etretinate Etretinate (trade name Tegison) is a medication developed by Hoffmann–La Roche that was approved by the FDA in 1986 to treat severe psoriasis. It is a second-generation retinoid. It was subsequently removed from the Canadian market in 1996 and t ...

has been used to treat the hair loss. In several dog breeds but also in

mongrel A mongrel, mutt, or mixed-breed dog is a dog that does not belong to one officially recognized breed, including those that result from intentional breeding. Although the term ''mixed-breed dog'' is sometimes preferred, many mongrels have no kn ...

s, dogs with the predisposition due to their coat genetics with the MLPH gene (

melanophilin Melanophilin is a carrier protein which in humans is encoded by the ''MLPH'' gene. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants has not been determined. ...

) suffer from colour dilution alopecia (CDA). Interestingly in

Great Dane The Great Dane is a German list of dog breeds, breed of large mastiff-sighthound, which descends from hunting dogs of the Middle Ages used to hunt bears, wild boar, and deer. They were also used as guardian dogs of German nobility. It is one o ...

s and

Weimaraner The is a German breed of hunting dog of medium to large size, with history going back at least to the nineteenth century. It originated in the area of the city of Weimar (then in Saxe-Weimar-Eisenach, now in the state of Thuringia), for which ...

s there are usually no problems due to the dilution gene. The reasons for this are not yet known.

Commonly affected breeds

Whippet The Whippet is a British breed of dog of sighthound type. It closely resembles the Greyhound and the smaller Italian Greyhound, and is intermediate between them in size. In the nineteenth century it was sometimes called "the poor man's raceh ...

Italian Greyhound The Italian Greyhound or Italian Sighthound () is an Italian dog breed, breed of small sighthound. It was bred to hunt European hare, hare and European rabbit, rabbit, but is kept mostly as a companion dog. History Small dogs of sighthound t ...

Chow Chow The Chow Chow is a spitz-type of dog breed originally from Northern China. The Chow Chow is a sturdily built dog, square in profile, with a broad skull and small, triangular, erect ears with rounded tips. The breed is known for a very dense do ...

Standard Poodle The Poodle, called the in German () and the in French, is a Dog breed, breed of water dog. The breed is divided into four varieties based on size, the Standard Poodle, Medium Poodle, Miniature Poodle and Toy Poodle, although the Medium Po ...

Yorkshire Terrier The Yorkshire Terrier, also known as a Yorkie, is a British breed of toy dog of terrier type. It is among the smallest of the terriers and indeed of all dog breeds, with a weight of no more than . It originated in the nineteenth century in the ...

* Silky Terrier * Chihuahua *

Boston Terrier The Boston Terrier is a breed of dog originating in the United States of America. This "American Gentleman" was accepted in 1893 by the American Kennel Club as a non-sporting breed. Boston Terriers are small and compact with a short tail and ere ...

Newfoundland Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the population ...

German Shepherd Dog The German Shepherd, also known in Britain as an Alsatian, is a German breed of working dog of medium to large size. The breed was developed by Max von Stephanitz using various traditional German herding dogs from 1899. It was originally b ...

Shetland Sheepdog The Shetland Sheepdog, also known as the Sheltie, is a breed of herding dog that originated in the Shetland Islands of Scotland. It was formally recognized by the Kennel Club in 1909. It was originally called the ''Shetland Collie'', but this c ...

Schipperke A Schipperke (; ) is a small breed of dog that is believed to have originated in the 1600s in Flanders.Alexandra Anastasio (January 31, 2017) American Kennel Club official websit "What Was the Schipperke Bred To Do"/ref> There has been a long in ...

Bernese Mountain Dog The Bernese Mountain Dog, or , is a large dog breed originating from the canton of Bern, Switzerland and the Swiss Alps. It is one of four Sennenhund-dog type, type breeds, with ancestral roots in Ancient Rome, Roman mastiffs. The name ''Berner ...

* Mudi

Black hair follicular dysplasia

Black hair follicular dysplasia only affects black fur. Affected fur will not grow back and dogs are likely to develop skin infections and follicular plugging. The condition is believed to be caused by an

autosomal recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The firs ...

trait. Breeds reported to be infected include the

, Jack Russell Terrier, King Charles Cavalier Spaniel,

Saluki The Saluki or Persian hound (Persian:سگ تازی، Arabic: سلوقي) is a standardised breed developed from sighthounds – dogs that hunt primarily by sight rather than strong scent – that was once used by nomadic tribes to run down game ...

Bearded Collie The Bearded Collie or Beardie is a British breed of herding dog of collie type. It was formerly used primarily by Scottish shepherds, but now commonly kept as a family companion. Weights are usually in the range , while height at the withers ...

Border Collie The Border Collie is a British list of dog breeds, breed of herding dog of the collie type of medium size. It originates in the region of the Anglo-Scottish border, and descends from the traditional Sheep dog, sheepdogs once found all over the ...

Beagle The Beagle is a small breed of scent hound, similar in appearance to the much larger foxhound. The beagle was developed primarily for hunting rabbit or hare, known as beagling. Possessing a great sense of smell and superior tracking inst ...

Basset Hound The Basset Hound is a short-legged breed of scent hound. The Basset Hound was developed in Great Britain from several now-extinct strains of France, French basset breeds. It was bred primarily for hunting rabbit and hare on foot, moving slowly en ...

Pointers Pointer may refer to: People with the name * Pointer (surname), a surname (including a list of people with the name) * Pointer Williams (born 1974), American former basketball player Arts, entertainment, and media * ''Pointer'' (journal), the ...

Gordon Setter The Gordon Setter is a Scottish large dog breed, breed of dog, a member of the setter family that also includes both the better-known Irish Setter and the English Setter. Setter breeds are classified as members of either the Sporting or Gundo ...

Doberman Pinscher The Dobermann is a German breed of medium-large working dog of pinscher type. It was originally bred in Thuringia in about 1890 by Louis Dobermann, a tax collector.

, Large Münsterländer‚ and

New Zealand Huntaway The Huntaway (also known as the New Zealand Huntaway) is a large, strongly-built breed of dog used for general sheep-herding tasks in New Zealand, where they originate. They were bred to use their loud, deep bark to drive sheep. The breed dates ...

Other types of follicular dysplasia

The

Siberian Husky The Siberian Husky is a dog breed, breed of medium-sized Working dog, working sled dog. The breed belongs to the Spitz genetic family. It is recognizable by its thickly furred Coat (dog), double coat, erect triangular ears, and distinctive mark ...

and

Alaskan Malamute The Alaskan Malamute () is a large breed of dog that was originally bred for its strength and endurance, to haul heavy freight as a sled dog. It is similar to other arctic breeds such as the husky, the spitz, the Greenland Dog, Canadian Eski ...

have a type of follicular dysplasia that occurs between the ages of three and four months, possibly later in the Malamute. The

guard hair Guard hair or overhair is the outer layer of hair of most mammals, which overlay the fur. Guard hairs are long and coarse and protect the rest of the pelage (fur) from abrasion and frequently from moisture. They are visible on the surface of the ...

s of the trunk are progressively lost and the coat turns reddish in color. In black or red

Dobermann The Dobermann is a German list of dog breeds, breed of medium-large working dog of pinscher type. It was originally bred in Thuringia in about 1890 by Karl Friedrich Louis Dobermann, Louis Dobermann, a tax collector.Miniature Pinscher The Miniature Pinscher, also known as the Zwergpinscher, Mini Pin and Min Pin for short, is a small breed of dog of the pinscher type originating in Germany. While the breed's visual similarities to the Toy Manchester Terrier, which somewhat resem ...

s, and

Manchester Terrier The Manchester Terrier is a breed of dog of the smooth-haired terrier type. It was first bred in the 19th century to control vermin, notably rats, at which it excelled. So efficient at the task was it that it often appeared in rat-baiting pits ...

s there is a type of follicular dysplasia that occurs between the ages of one and four years. It begins in the flank and spreads to the back.

References

{{refend Follicular dysplasia