Mite infestation - young, old, immunocompromised at risk - common clinical signs: skin lesions, hair loss, crusty skin - diagnostics: skin scrape (important to get deep, mite burrow)

Host-adapted variants/strains - can be zoonotic, humans also have their own variant - wide range of hosts (canids, swine, ferrets) - severe disease in red foxes, immunocompromised hosts (crusted scabies)

Wild or domestic felids - lesions begin on ears, face, neck --> feet/perineum - thick, scaly skin, alopecia, pruitus --> self trauma, systemic - potentially zoonotic

Cattle, sheep, horses - primarily southwest - reportable

Mites Flashcards by Kara Majors

Are mites arachnids?

Yes

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How do mites differ from ticks?

size
time/location on host
same life cycle stages
same aspects of morphology

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Mite mouth parts

Have structures that will scrape skin, do not penetrate

- feed on skin secretions, or chew on skin

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Acariasis

Mite infestation

young, old, immunocompromised at risk
common clinical signs: skin lesions, hair loss, crusty skin
diagnostics: skin scrape (important to get deep, mite burrow)

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Are mites zoonotic?

Yes

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Sarcoptes scabiei

Host-adapted variants/strains

can be zoonotic, humans also have their own variant
wide range of hosts (canids, swine, ferrets)
severe disease in red foxes, immunocompromised hosts (crusted scabies)

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Does Sarcoptes scabiei affect cats?

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S. scabiei motile stages

Larvae, nymphal, adult

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S. scabiei life cycle

Occurs on host, mostly in epidermis over 2-3 weeks

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Sarcoptic mange usually affects ______ areas first

Hairless

papules, erythema, pruritus = hyperkeratosis, alopecia
self trauma, secondary infections, crusting
may be fatal

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Dog

Itch mite

- lateral elbows, lateral hocks, edge of pinna

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Swine

Ears. back

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Cattle

Barn itch

- abdomen, neck, medial hind legs

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Sheep/goats

Head scab

- face, ears, ventrum

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Horses

Neck, shoulders, face

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When is Sarcoptes scabiei reportable?

Sheep, goats, horses

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Sarcoptic mange diagnosis

Skin scrapings (deep)
- negative scrapings NOT conclusive
- PCR
History
Response to treatment

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Sarcoptic mange treatment

Various acaricides

dips
avermectins

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Notoedres cati

Wild or domestic felids

lesions begin on ears, face, neck –> feet/perineum
thick, scaly skin, alopecia, pruitus –> self trauma, systemic
potentially zoonotic

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Is N. cati a problem for rabbits?

Yes, households with cats and rabbits should treat both

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Psoroptes cuniculi

Common ear mites

- hosts: rabbits, goats, horses

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Psoroptes ovis

Cattle, sheep, horses

primarily southwest
reportable

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Psoroptes spp. life cycle

Non-burrowing on skin

P. ovis of cattle

Cattle scab

- back, tail head, shoulders

P. ovis of sheep

Neck, back

P. ovis of horses

Base of mane

Psoroptes ovis is reportable in

Cattle, sheep

Chorioptes spp

Most common mite of cattle, horses - also in small ruminants - NOT reportable! - chorioptic mange: mild or no clinical signs - non-burrowing

Chorioptes in cattle

Foot and tail mange, tail scab | - base of tail, udder, hind feet

Chorioptes in sheep, goats

Foot and tail mange | - interdigital, base of tail, scrotum (sheep)

Chorioptes in horses

Foot mange, itchy leg - foot, base of tail - especially occurs in draft breeds

Otodectes cynotis

Dogs, cats, ferrets (is transferable among different animal species) - common ear mite - mites in external ear canal

Ear mites

Canals become excessively moist - inflammation --> pruritus --> self trauma - secondary infection, ruptured ear drum - bilateral

Purulent black exudate

Cerumen

Otodectes cynotis - diagnosis

Ear swabs | - all dogs, cats in household need to be treated

Demodex spp.

Most species are normal fauna of skin - transmission by direct contact (mother) --> neonate - immunosuppression --> overgrowth --> disease

Which demodex species is a primary pathogen?

D. cornei

Demodex life cycle

All stages develop on host within hair follicle lumen and sebaceous gland ducts

Squamous demodicosis

Localized or generalized - primarily dogs - seen in cats, horses, sheep - dry, scaly dermatitis, alopecia

Papulonodular demodicosis

Cattle, goats, pigs | - hair follicles/glands obstructed --> nodules

Localized demodectic mange in dogs

Small, well-defined patchy lesions - young (less than 1 year) - self limiting with spontaneous recovery

Generalized demodectic mange in dogs

Usually underlying disease - large coalescing lesions (pruritus, secondary infection) - no age predilection - poor prognosis if no aggressive treatment

Is demodex pruritic on its own?

No, requires secondary infection

Feline demodectic mange

Rare - D. cati is normal flora (eyelids, head, neck) - D. gatoi is transmissible = pruritus, superficial (ventrum limbs) --> is a primary pathogen

Demodectic mange - cattle

Common in pregnant, lactating cows | - nodular, neck, shoulders

Demodectic mange - sheep

Rare | - diffuse, scaly, neck, flank, shoulders

Demodectic mange - goats

Young or pregnant | - nodular, face, neck, axilla, udder

Demodectic mange - horses

Rare, chronic corticosteroids | - diffuse, scaly

Demodectic mange - pigs

Rare | - nodular, snout

Cheyletiella

Dog, cats - very contagious, potentially zoonotic! - walking dandruff - nonburrowing

Cheyletiella clinical signs

- dogs: exfoliative dermatitis, inflammation, hyperaesthesia | - cats: long haired breeds, similar signs as dog on head/trunk

Pneumonyssoides caninum

Dog - nasal mite! - rhinitis, hyperemic mucosa - diagnose via rhinoscopy, nasal swab

Knemidocoptes mutans

Chickens, pet birds | - severe hyperkeratosis

Dermanyssus gallinae

Chickens, wild birds | - anemia: decreased production

Ornithonyssus sylvarium

Chickens, turkeys | - anemia: soiled vent feathers