Demodicosis, also called demodectic mange or red mange, is caused by a sensitivity to and overpopulation of Demodex canis

Demodex mite

Demodex is a genus of tiny parasitic mites that live in or near hair follicles of mammals. About 65 species of Demodex are known; they are among the smallest of arthropods. Two species living on humans have been identified: Demodex folliculorum and Demodex brevis, both frequently referred to as...

as the animal's immune system is unable to keep the mites under control.

Demodex is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of mite

Mite

Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology.-Diversity and systematics:...

 in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Demodicidae. Demodex canis occurs naturally in the hair follicles of most dogs in low numbers around the face and other areas of the body. In most dogs, these mites never cause problems. However, in certain situations, such as an under-developed or impaired immune system

Immune system

An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...

, intense stress

Stress (medicine)

Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...

, or malnutrition

Malnutrition

Malnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess , or in the wrong proportions....

, the mites can reproduce rapidly, causing symptoms in sensitive dogs that range from mild irritation and hair loss on a small patch of skin to severe and widespread inflammation, secondary infection, and—in rare cases—a life-threatening condition. Small patches of demodicosis often correct themselves over time as the dog's immune system matures, although treatment is usually recommended.

Presentation

Minor cases of demodectic mange usually do not cause much itching but might cause pustules on the dog's skin, redness, scaling, hair loss, or any combination of these. It most commonly appears first on the face, around the eyes, or at the corners of the mouth, and on the forelimbs and paws.

In the more severe form, hair loss can occur in patches all over the body and might be accompanied by crusting, pain, enlarged lymph nodes, and deep skin infections.

Demodectic mange is transmitted from host to host through direct contact. Typically animals become infected through nursing from their mother. Demodex mites are host-adapted; there is no zoonotic potential in either canine or feline demodicosis. These mites (Demodex canis) thrive only on their specific hosts (dogs). The transmission of these mites from mother to pup is normal (which is why the mites are normal inhabitants of the dog's skin), but some individuals are sensitive to the mites due to a cellular immune deficiency, underlying disease, stress, or malnutrition , which can lead to the development of clinical demodectic mange.

These diseases in human

Human

Humans are the only living species in the Homo genus...

s is usually caused by Demodex folliculorum (not the same species affecting dogs)and is usually called demodicosis which may have a rosacea

Rosacea

Rosacea is a chronic condition characterized by facial erythema . Pimples are sometimes included as part of the definition. Unless it affects the eyes, it is typically a harmless cosmetic condition...

-like appearance. Common symptoms include hair

Hair

Hair is a filamentous biomaterial, that grows from follicles found in the dermis. Found exclusively in mammals, hair is one of the defining characteristics of the mammalian class....

 loss, itching and inflammation

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

. An association with pityriasis

Pityriasis

Pityriasis commonly refers to flaking of the skin. The word comes from the Greek πίτυρον "bran".-Classification:Types include:* Pityriasis alba* Pityriasis lichenoides chronica* Pityriasis lichenoides et varioliformis acuta...

 folliculorum has also been described.

Some breeds appear to have an increased risk of mild cases as young dogs, including the Afghan Hound

Afghan Hound

The Afghan Hound is one of the oldest sighthound dog breeds. Distinguished by its thick, fine, silky coat and its tail with a ring curl at the end, the breed acquired its unique features in the cold mountains of Afghanistan, where it was originally used to hunt hares and gazelles by coursing them....

, American Staffordshire Terrier

American Staffordshire Terrier

The American Staffordshire terrier is a medium-sized, short-coated American dog breed. In the early part of the twentieth century the breed gained social stature and was accepted by the American Kennel Club as the American Staffordshire Terrier in 1936...

, Boston Terrier

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. Color and markings are important when distinguishing this breed to the AKC standard. They should be either black,...

, Boxer

Boxer (dog)

Developed in Germany, the Boxer is a breed of stocky, medium-sized, short-haired dog. The coat is smooth and fawn or brindled, with or without white markings. Boxers are brachycephalic , and have a square muzzle, mandibular prognathism , very strong jaws and a powerful bite ideal for hanging on to...

, Chihuahua

Chihuahua (dog)

The ' is the smallest breed of dog and is so named for the state of Chihuahua in Mexico. Chihuahuas come in a wide variety of sizes, head shapes, colors and coat lengths.-History:...

, Chow Chow

Chow Chow

Chow chow is a breed of dog that was developed in China, where it is referred to as Songshi Quan , which literally means "puffy-lion dog".- Appearance :...

, Shar Pei

Shar Pei

The Shar Pei, or Chinese Shar-Pei, is a breed of dog known for its distinctive features of deep wrinkles and a blue-black tongue. The breed comes from China. The name translates to "sand skin" and refers to the texture of its short, rough coat...

, Collie

Collie

The collie is a distinctive type of herding dog, including many related landraces and formal breeds. It originates in Scotland and Northern England. It is a medium-sized, fairly lightly built dog with a pointed snout, and many types have a distinctive white pattern over the shoulders. Collies...

, Dalmatian

Dalmatian (dog)

The Dalmatian is a breed of dog whose roots are often said to trace back to Dalmatia, a region of Croatia where the first illustrations of the dog have been found. The Dalmatian is noted for its unique black- or brown-spotted coat and was mainly used as a carriage dog in its early days...

, Doberman Pinscher

Dobermann

The Doberman Pinscher or simply Doberman, is a breed of domestic dog originally developed around 1890 by Karl Friedrich Louis Dobermann. Doberman Pinschers are among the most common of pet breeds, and the breed is well known as an intelligent, alert, and loyal companion dog...

, Bulldog

Bulldog

Bulldog is the name for a breed of dog commonly referred to as the English Bulldog. Other Bulldog breeds include the American Bulldog, Olde English Bulldogge and the French Bulldog. The Bulldog is a muscular heavy dog with a wrinkled face and a distinctive pushed-in nose...

, English Bull Terrier, Miniature Bull Terrier, German Shepherd Dog

German Shepherd Dog

The German Shepherd Dog , also known as an Alsatian or just the German Shepherd, is a breed of large-sized dog that originated in Germany. The German Shepherd is a relatively new breed of dog, with its origin dating to 1899. As part of the Herding Group, the German Shepherd is a working dog...

, Great Dane

Great Dane

The Great Dane , also known as German Mastiff or Danish Hound , is a breed of domestic dog known for its giant size...

, Old English Sheepdog

Old English Sheepdog

The Old English Sheepdog is a large breed of dog which was developed in England from early herding types of dog. The Old English Sheepdog has very long fur covering the face and eyes...

, American Pit Bull Terrier

American Pit Bull Terrier

The American Pit Bull Terrier is a medium-sized, solidly built, short haired dog whose early ancestors came from England and Ireland...

, West Highland White Terrier

West Highland White Terrier

The West Highland White Terrier, commonly known as the Westie, is a Scottish breed of dog with a distinctive white coat. The modern breed is descended from a number of breeding programes of white terriers in Scotland prior to the 20th century...

, Rat Terrier

Rat Terrier

The Rat Terrier is an American dog breed with a rich and varied background as an all-around farm dog and hunting companion. Traditionally more of a type than a breed, they share much ancestry with the tough little mixed-breed dogs known as feists...

, and Pug

Pug

The pug is a "toy" breed of dog with a wrinkly, short-muzzled face, and curled tail. The breed has a fine, glossy coat that comes in a variety of colors, and a compact square body with well-developed muscle. They have been described as multum in parvo , referring to the pug's personality and...

.

Demodectic mange also occurs in other domestic and wild animals. The mites are specific to their hosts, and each mammal species is host to one or two unique species of Demodex mites. There are two types of demodectic mange in cats. Demodex cati causes follicular mange, similar to that seen in dogs, though it is much less common. Demodex gatoi is a more superficial form of mange, causes an itchy skin condition, and is contagious amongst cats.
It has recently manifested itself in mountain lions in the Rocky Mountain region. The DNR has reported an outbreak or epidemic within the Utah County area. These infected and mange-ridden cats are being shot on sight.

Treatment

Localized demodectic mange is considered a common puppyhood ailment, with roughly 90% of cases resolving on their own with no treatment. Minor, localized cases should be left to resolve on their own to prevent masking of the more severe generalized form. If treatment is deemed necessary Goodwinol, a rotenone-based insecticide ointment is often prescribed, but it can be irritating to the skin. Demodectic mange with secondary infection is treated with antibiotic

Antibiotic

An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...

s and medicated shampoos.

In more severe generalized cases, Amitraz

Amitraz

Amitraz is an antiparasitic drug. Product names include Ridd, Aazdieno, Acarac, Aludex, Amitraze, Avartin, Baam, Edrizan, Maitac, Mitac, Mitaban, Triatox, Triatix, Vapcozin Taktic, Triazid, Topline, Tudy, Ectodex, Garial, Danicut, Ovidrex, Acadrex, Bumetran, and Ovasyn.It is an alpha-adrenergic...

 is a parasiticidal dip that is licensed for use in many countries (the only FDA approved treatment in the USA) for treating canine demodicosis. It is applied weekly or biweekly, for several weeks, until no mites can be detected by skin scrapings. Demodectic mange in dogs can also be managed with avermectin

Avermectin

The avermectins are a series 16-membered macrocyclic lactone derivatives with potent anthelmintic and insecticidal properties. These naturally occurring compounds are generated as fermentation products by Streptomyces avermitilis, a soil actinomycete...

s, although there are few countries which license these drugs, which are given by mouth, daily, for this use. Ivermectin is used most frequently; collie

Collie

The collie is a distinctive type of herding dog, including many related landraces and formal breeds. It originates in Scotland and Northern England. It is a medium-sized, fairly lightly built dog with a pointed snout, and many types have a distinctive white pattern over the shoulders. Collies...

-like herding breeds often do not tolerate this drug due to a defect in the blood-brain barrier

Blood-brain barrier

The blood–brain barrier is a separation of circulating blood and the brain extracellular fluid in the central nervous system . It occurs along all capillaries and consists of tight junctions around the capillaries that do not exist in normal circulation. Endothelial cells restrict the diffusion...

, though not all of them have this defect. Other avermectin drugs that can be used include doramectin

Doramectin

Doramectin is a veterinary drug approved by the Food and Drug Administration for the treatment of parasites such as gastrointestinal roundworms, lungworms, eyeworms, grubs, sucking lice and mange mites in cattle....

 and milbemycin

Milbemycin

The milbemycins are a group of macrolides chemically related to the avermectins and were first isolated in 1972 from Streptomyces hygroscopicus.They are used in veterinary medicine as antiparasitic agents against worms, ticks and fleas....

.

Cats with Demodex gatoi must be treated with weekly or bi-weekly sulfurated lime rinses. Demodex cati are treated similarly to canine demodicosis.

Because of the possibility of the immune deficiency being an inherited trait many veterinarians believe that all puppies with generalized demodex should be spayed or neutered and not reproduce. Females with generalized demodex should be spayed because the stress of the estrus cycle will often bring on a fresh wave of clinical signs.

Diagnosis

For demodectic mange, properly performed deep skin scrapings generally allow the veterinarian to identify the microscopic mites. However because the mite is a normal inhabitant of the dog's skin, the presence of the mites does not conclusively mean the dog suffers from demodex. Rather abnormally high numbers of the mite are more useful. In breeds such as the West Highland White Terrier

West Highland White Terrier

The West Highland White Terrier, commonly known as the Westie, is a Scottish breed of dog with a distinctive white coat. The modern breed is descended from a number of breeding programes of white terriers in Scotland prior to the 20th century...

, relatively minor skin irritation which would otherwise be considered allergy should be carefully scraped because of the predilection of these dogs to demodectic mange. Skin scrapings may be used to follow the progress of treatment in demodectic mange.