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==Description==

An inflammatory parasitic disease of dogs and cats caused by [[Demodex]]. The mites are host-specific and can occur in dogs, cats, cattle, sheep, goats, pigs and horses. There has to be an increased number of immature mites to classify as an infestation. The mite is transmitted from dam to offspring during nursing. The mites live in hair follicles and infestation may lead to secondary bacterial infection and furunculosis.  

 

==Introduction==

An inflammatory parasitic disease of dogs and cats caused by ''[[Demodex]]''. The mites are host-specific and can occur in dogs, cats, cattle, sheep, goats, pigs and horses. There has to be an increased number of immature mites to classify as an infestation. The mite is transmitted from dam to offspring during nursing. The mites live in hair follicles and infestation may lead to secondary bacterial infection and furunculosis.  

==Signalment==

==Signalment==

'''Breed predilections''':

'''Breed predilections''':

Demodicosis is usually a disease of short haired dogs and is more common in pedigree breeds. Within [[Canine Breeds - WikiNormals|dog breeds]], the Staffordshire bull terrier, German Shepherd dog, Old English sheepdog, Collies and Dalmations are at risk. Additionally within [[Feline Breeds - WikiNormals|cat breeds]] it has been reported that there is an increased incidence in Siamese and Burmese cats.

Demodicosis is usually a disease of short haired dogs and is more common in pedigree breeds. Within [[Canine Breeds - WikiNormals|dog breeds]], the Staffordshire bull terrier, German Shepherd dog, Old English sheepdog, Collies and Dalmatians are at risk. Additionally within [[Feline Breeds - WikiNormals|cat breeds]] it has been reported that there is an increased incidence in Siamese and Burmese cats.

'''Age predilections''':

'''Age predilections''':

Often animals less than 12 months of age are affected although adult onset is recognised.  

Often animals less than 12 months of age are affected although adult onset is recognised.  

==Clinical Signs==

==Clinical Signs==

Crusting, hair loss, grey hyperpigmentation and plugged follicles are typical findings in animals suffering from demodicosis.

Crusting, hair loss, grey hyperpigmentation and plugged follicles are typical findings in animals suffering from demodicosis.

'''Dogs:'''

===Dogs===

May be localised or generalised.

May be localised or generalised.

A lymphadenopathy and pyrexia are also common features. Pododemodicosis can occur with the generalised form and can persist after other lesions have resolved or appear in isolation. This manifests as erythema and secondary infection of the feet.   

A lymphadenopathy and pyrexia are also common features. Pododemodicosis can occur with the generalised form and can persist after other lesions have resolved or appear in isolation. This manifests as erythema and secondary infection of the feet.   

'''Adult Onset Demodicosis:''' Can present as generalised disease or focal alopecia . Onset in adulthood is often associated with internal disease such as ([[Adrenal Glands - Pathology#Adrenal Hyperfunction|hyperadrenocorticism]], immunosuppression or neoplasia. Long term use of glucocorticoids in the West Highland white terrier has been associated with adult onset demodicosis.

'''Adult Onset Demodicosis:''' Can present as generalised disease or focal alopecia . Onset in adulthood is often associated with internal disease such as ([[Hyperadrenocorticism|hyperadrenocorticism]], immunosuppression or neoplasia. Long term use of glucocorticoids in the West Highland white terrier has been associated with adult onset demodicosis.

 

'''Cats:'''

===Cats===

Often multifocal alopecia particularly of the eyelids, periocular region, head and neck. Erythema scale and crust may be present with varying degrees of pruritis. Otodemodicosis which manifests as an erythematous ceruminous otitis has also been reported in the cat.

Often multifocal alopecia particularly of the eyelids, periocular region, head and neck. Erythema scale and crust may be present with varying degrees of pruritus. Otodemodicosis which manifests as an erythematous ceruminous otitis has also been reported in the cat.

   

   

'''Cattle''':

===Cattle===

Pea-sized nodules are present over the body. Each nodule contains several thousand mites. Affects hide quality and is economically important in Australia.

Pea-sized nodules are present over the body. Each nodule contains several thousand mites. Affects hide quality and is economically important in Australia.

   

 

==Laboratory Tests==

 

 

 

 

 

 

 

Microscopic examination of deep skin scraping reveals the cigar-shaped adult [[Demodex| ''Demodex'']] mites (eight legs), larval forms (six legs) and lemon-shaped eggs in high numbers. Hair plucks can also demonstrate mites microscopically. As mites are often residents in normal skin, detecting mites on a skin scrape may not always provide a definitive diagnosis - results should be combined with the entire clinical picture. The absence of mites on multiple skin scrapes may allow you to rule out the disease.  

 

===Laboratory Tests===

Haematology and Biochemistry may be useful in identifying an underlying cause in adult onset demodicosis.

Haematology and Biochemistry may be useful in identifying an underlying cause in adult onset demodicosis.

==Biopsy==

===Biopsy===

Cutaneous biopsy may be necessary if lesions are chronic, granulomatous or fibrotic.

Cutaneous biopsy may be necessary if lesions are chronic, granulomatous or fibrotic.

==Treatment==

==Treatment==

Localised demodicosis in young dogs will often resolve spontaneously.

Localised demodicosis in young dogs will often resolve spontaneously.

In cases of generalised demodicosis: Amitraz (Aludex) should be used as a dip weekly until there is a resolution of clinical signs and skin scrapes are negative for the mite. The mites are not easily accessible to acaricides due to their deep location in the skin and to aid amitraz penetration, clipping a dog's coat and washing with benzoyl peroxide shampoo prior to application is recommended.  Side effects of this treatment include lethargy, anorexia, depression, vomiting and diarrhoea.  

 

A spot on treatment containing imidacloprid and moxidectin (advocate) is also licenced to treat demodicosis.  

In cases of generalised demodicosis: Amitraz (Aludex, Intervet/Schering-Plough Animal Health) should be used as a dip weekly until there is a resolution of clinical signs and skin scrapes are negative for the mite. The mites are not easily accessible to acaricides due to their deep location in the skin and to aid amitraz penetration, clipping a dog's coat and washing with benzoyl peroxide shampoo prior to application is recommended.  Side effects of this treatment include lethargy, anorexia, depression, vomiting and diarrhoea.  

 

A spot on treatment containing imidacloprid and moxidectin (Advocate, Bayer) is also licenced to treat demodicosis. An alternative licensed product is an amitraz and metaflumizone spot on (Promeris Duo, Pfizer AH).

 

Any secondary pyoderma present on the animal must also be treated with appropriate antibiotics.

Any secondary pyoderma present on the animal must also be treated with appropriate antibiotics.

If the amitraz and imidacloprid-moxidecin combinations are ineffective or not tolerated ivermectin or milbemycin can be given daily. This treatment is off-licence and requires informed owner consent as well as monitoring of the animal for signs of neurological side effects.

If the amitraz and imidacloprid-moxidecin combinations are ineffective or not tolerated ivermectin or milbemycin can be given daily. This treatment is off-licence and requires informed owner consent as well as monitoring of the animal for signs of neurological side effects.

Prognosis is good for localised cases. Generalised demodicosis is often managed medically however many cases are controlled rather than cured. Owners must be educated about the disease and be advised not to breed from animals with the generalised form.

Prognosis is good for localised cases. Generalised demodicosis is often managed medically however many cases are controlled rather than cured. Owners must be educated about the disease and be advised not to breed from animals with the generalised form.

Adult-onset dogs are often refractory to treatment.

Adult-onset dogs are often refractory to treatment.

==References==

==References==

Tilley, L.P, Smith, F.W.K. (2004) The 5-minute veterinary consult. canine and feline. (3rd edition). Lippincott Williams and Wilkins.

 

 

 

Tilley, L.P, Smith, F.W.K. (2004) '''The 5-minute veterinary consult, canine and feline.''' (3rd edition). Lippincott Williams and Wilkins.

4th year BvetMed Dermatology Notes. RVC 2008

4th year BvetMed Dermatology Notes. RVC 2008

 

 

[[Category:To_Do_-_Caz]]

[[Category:Expert_Review - Small Animal]][[Category:Dermatological Diseases - Dog]][[Category:Dermatological Diseases - Cat]]

[[Category:Integumentary System - Mite Infections]]