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| − | {{toplink
| + | #REDIRECT[[:Category:Integumentary System - Parasitic Infections]] |
| − | |backcolour = FFCCCC
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| − | |linkpage =Integumentary System - Pathology
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| − | |linktext =Integumentary System
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| − | |maplink = Integumentary System (Content Map) - Pathology
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| − | |pagetype =Pathology
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| − | |sublink1 = Skin Infectious - Pathology
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| − | |subtext1 = SKIN INFECTIOUS
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| − | }}
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| − | <br>
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| − | ==Mites==
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| − | ===Demodicosis===
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| − | *[[Suborder: Astigmata, astigmatid mites|''Demodex'']] are normal inhabitants of hair follicles and sebaceous glands
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| − | *Have to have increased number of immature mites to classify as infestation
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| − | *Host-specific
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| − | *Occurs in dogs, cattle, sheep, goats, pigs, horses and cats
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| − | *Transmits during nursing from dam to offspring
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| − | *''Demodex canis'' in dogs:
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| − | **Generalised or localised
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| − | **Mainly young dogs affected or adults with other disease ([[Adrenal Glands - Pathology#Adrenal Hyperfunction|hyperadrenocorticism]], [[Thyroid Gland - Pathology#Hypothyroidism|hypothyroidism]])
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| − | **Often inherited in pure bred
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| − | **Grossly:
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| − | ***Localised: scaly, erythematous, macular, alopecic areas; usually face or front legs
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| − | ***Generalised: large, coalescing lesions, patches, erythema, alopecia, scales, crusts
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| − | **Microscopically:
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| − | ***Localised: lymphoplasmacytic perifolliculitis with hyperkeratinisation, sebaceous adenitis, low pigment, intraluminal mites
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| − | ***Generalised: perifolliculitis and follicular hyperkeratosis, follicular pluggingf, bacterial proliferation, bacterial neutrophilic folliculitis
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| − | ****May cause folliculat rupture -> furunculosis, cellulitis, lymphadenitis and septicaemia
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| − | | |
| − | | |
| − | ===Scabies===
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| − | *Caused by [[Suborder: Astigmata, astigmatid mites|''Sarcoptes scabiei'']]
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| − | *Highly contagious
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| − | *Mainly in pigs, dogs, also horses, cattle, sheep, goats and cats
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| − | *Intense pruritus due hypersensitivity to mites borrowing through stratum corneum
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| − | *Usually starts with external pinnae -> head -> neck -> generalised
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| − | *Grossly:
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| − | **Erythematous [[Skin Glossary - Pathology|macules, papules, crusts]]
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| − | **If chronic -> [[Skin Glossary - Pathology|lichenified]], hairless
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| − | *Microscopically:
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| − | **Hyperplastic, spongiotic, superficial perivascular dermatitis
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| − | **Crusting, eosinophil infiltration
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| − | **Mites are not commonly seen, but eggs and feces may be found in stratumn corneum
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| − | | |
| − | | |
| − | ===Notoedric mites===
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| − | *Rare but very contagious
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| − | *Caused by [[Suborder: Astigmata, astigmatid mites|''Notoedres cati'']]
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| − | *Grossly:
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| − | **Erythematous papular rash -> scales, crusts, alopecia -> lichenification when chronic
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| − | **Start on neck and ears -> head, face, paws -> generalised
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| − | *Microscopically:
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| − | **Epidermal hyperplasia, spongiosis, crusts
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| − | **Superficial perivascular dermatitis
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| − | **Eosinophils
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| − | | |
| − | | |
| − | ===Otodectic mites===
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| − | *Caused by [[Suborder: Astigmata, astigmatid mites|''Otodectes cynotis'']]
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| − | *In external ear canals of carnivores, occasionally elsewhere
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| − | | |
| − | | |
| − | ===Psoroptic mites===
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| − | *Occurs in cattle, sheep, horses, goats, rabbits and other animals
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| − | *Host-specific
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| − | *[[Suborder: Astigmata, astigmatid mites#Psoroptes cuniculi|''Psoroptes cuniculi'']] in ear canals of rabbits, horses, goats and sheep
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| − | *[[Suborder: Astigmata, astigmatid mites|''P.equi'']] at base of mane, ttail and forelock in horses
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| − | *[[Suborder: Astigmata, astigmatid mites|''P.ovis'']] in sheep ('''sheep scab''')and cattle
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| − | **Thickened skin and dry scales and crusts
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| − | **Starts at withers and spreads due to self trauma
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| − | **Microscopically:
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| − | ***Spongiotic, hyperplastic or exudative superficial perivascular dermatitis
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| − | ***Eosinophils
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| − | | |
| − | | |
| − | ===Chorioptic mites===
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| − | *Host-specific
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| − | *In cattle, horses, goats
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| − | *Caused by [[Suborder: Astigmata, astigmatid mites|''Chorioptes'' spp.]]
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| − | *Grossly:
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| − | **Erythematous, papular, crusty lesions
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| − | **Hairless, thickened skin
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| − | **Areas usually affected:
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| − | ***Horses: lower hind legs
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| − | ***Cattle: lower hind legs, scrotum, perineum, tail, udder, thigh
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| − | ***Sheep: lower hind legs and scrotum
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| − | ***Goats: lower hind legs, hindquarters, abdomen
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| − | | |
| − | | |
| − | ===Cheyletiellosis===
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| − | *Caused by ''Cheyletiella'' sp.]]
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| − | *Occurs in dogs, cats, rabbits, humans and wild animals
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| − | *In dogs and cats: hyperkeratosis - dry, white, scaly dandruff along back
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| − | *May be asymptomatic
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| − | *Grossly:
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| − | **Focal, multifocal or generalised red papules or crusts
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| − | *Microscopically:
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| − | **Superficial perivascular dermatitis
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| − | **Eosinophils
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| − | | |
| − | | |
| − | ===Trombiculidiasis===
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| − | | |
| − | *Harvest mite infestation (chiggers) - [[Suborder: Astigmata, astigmatid mites|''Trombicula'' sp.]]
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| − | *Form tunnels in epidermis by injecting saliva - eat digested tissue fluid
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| − | *Intense pruritus
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| − | *Grossly:
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| − | **Small, red [[Skin Glossary - Pathology|papules or crusts]]
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| − | **Orange to red larvae
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| − | **On skin close to plants or the ground
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| − | *Microscopically:
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| − | **Hyperplastic, superficial perivascular dermatitis
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| − | **[[Eosinophils - Anatomy & Physiology|Eosinophils]], [[Mast cells - Anatomy & Physiology|mast cells]]
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| − | **Intraepidermal mites
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| − | | |
| − | ==Ticks==
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| − | | |
| − | *Local reaction depends on host hypersensitivity and [[Suborder: Metastigmata, ticks|tick's]] secretions
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| − | *Grossly:
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| − | **Focal erosions, erythema, crusted ulcers, sometimes alopecia and nodules
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| − | *Microscopically:
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| − | **Epidermal and dermal necrosis
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| − | **Perivascular of diffuse inflammation and necrotic margins
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| − | **Eosinophils, macrophages and lymphocytes in exudate
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| − | **May form granulomas containing collagenous fibres and lymphoid follicles within dermis
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| − | | |
| − | ==Lice==
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| − | | |
| − | *Infestation is called '''pediculosis'''
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| − | *May cause anaemia (sucking lice), weakness, discomfort and damage to hair or wool
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| − | *More common in low temperatures when hair is longer
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| − | *Host-specific
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| − | *Spread by direct contact
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| − | *Most lesions are due to self-inflicted trauma
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| − | *Grossly:
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| − | **Papules, crusts, secondary excoriations
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| − | **Eggs and lice visible in lesions
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| − | | |
| − | ==Fleas==
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| − | *Occurs in cats and dogs mainly
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| − | *Irritation caused by enzymes, anticoagulants and histamine-like substances
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| − | *[[Skin - immunologic|Hypersensitivity]] to flea saliva may develop
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| − | *Young or small animals may suffer from aneamia
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| − | *Lesions normally in dorsolumbosacral region, caudomedial thighs, ventral abdomen, flank, neck (cats)
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| − | *Grossly:
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| − | **Red papules and secondary excoriations
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| − | | |
| − | ==[[Insecta|Flies]]==
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| − | *Bites may cause irritation, anaemia, toxicity or hypersensitivity
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| − | *Grossly:
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| − | **Wheals and papules around puncture wound
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| − | **Hair loss, scales, crusts, erythema
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| − | *Microscopically:
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| − | **Superficial perivascular dermatitis
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| − | **Eosinophilic folliculitis, +/- furunculosis
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| − | **Intraepidermal pustules
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| − | **Eosinophils and necrosis
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| − | | |
| − | ===Myiasis===
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| − | *Infection by dipterous flies in moist body areas (''eg.'' perineum)
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| − | *Commonly affects sheep - [[Bacterial skin infections - Pathology#Ovine fleece rot|ovine fleece rot]]
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| − | *Grossly:
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| − | **Matted hair or wool, may be in wounds
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| − | **Multiple holes or ulcers
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| − | **Malodour
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| − | *May result in death due to septicaemia or toxaemia
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| − | *'''Cuterebra myiasis'''
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| − | **Caused by ''Cuterebra'' sp
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| − | **Young animals come into contact with eggs on stones or plants
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| − | **Nodules with larvae in subcutis + respiration openings to surface
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| − | *'''Hypoderma myiasis'''
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| − | **Caused by ''Hypoderma lineatum'' or ''H. bovis''
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| − | **Mainly affects cattle
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| − | **Skin of legs is penetrated -> migration through [[Oesophagus - Anatomy & Physiology|oesophagus]] or vertebral canal to subcutis of back
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| − | **Cause subcutaneous nodules with respiration openings
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| − | **Larvae in cavity with fibrin and eosinophils surrounded by granulation tissue with eosinophil clusters
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| − | *'''Screwworm myiasis'''
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| − | **Occurs in Africa, Asia, Central and South America
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| − | **Larvaae are deposited in wounds
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| − | **Penetrate and liquify tissue
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| − | | |
| − | ==Helminths==
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| − | | |
| − | ===Hookworms===
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| − | *Caused by [[Ancylostomatoidea|''Ancylostoma'' or ''Uncinaria'']]
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| − | *Grossly:
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| − | **Red papules -> lichenified alopecic areas
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| − | **Mainly of dog feet
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| − | **Foot pads may soften with keratinised area separation
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| − | **Possible secondary bacterial dermatitis and [[Skin Glossary - Pathology|paronychia]]
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| − | *Microscopically:
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| − | **Hyperplastic spongiotic perivascular dermatitis
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| − | **Eosinophils
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| − | **Crusts
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| − | **Migration tracts
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| − | | |
| − | ===Cutaneous habronemiasis===
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| − | | |
| − | *In horses (also calles '''summer sores''')
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| − | *Caused by ''Habronema'' sp. or ''Draschia'' sp. - spread by [[Insecta|house flies or stable flies]]
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| − | *In traumatised or moist soft skin
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| − | *Grossly:
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| − | **Single or multiple tomorous masses that proliferate and ulcerate
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| − | **Red to brown, on section have small gritty yellow to white foci
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| − | *Microscopically:
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| − | **Nodular dermatitis
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| − | **Eosinophils, epithelioid macrophages, multinucleated giant cells
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| − | **Larvae and necrotic tissue
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| − | **Granulation tissue with neutrophils along ulcerated surface
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| − | | |
| − | ===Onchocerciasis===
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| − | | |
| − | *Caused by [[Onchocerca spp.|''Onchocerca'' spp.]]
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| − | *Affects horses, cattle, donkeys, mules, sheep, goats
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| − | *Transmitted by [[Insecta|Simulidae and Ceratopogonidae]]
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| − | *Hypersensitivity varies with individuals, may occur without any inflammation
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| − | *Grossly:
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| − | **Adult parasites within connective tissue nodules
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| − | **Microfilaria in dermis, especially ventral midline
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| − | **Patchy alopecia, erythema, scaling, crusting, change in pigmentation
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| − | **Circular areas of dermatitis on forehead appears in some horses
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| − | **May also involve keratitis, uveitis and conjunctivitis
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| − | *Microscopically:
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| − | **Normal to superficial to deep perivascular dermatitis
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| − | **Eosinophils, lymphocytes, microfilariae
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| − | | |
| − | ===Stephanofilariasis===
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| − | | |
| − | *Caused by [[Stephanofilaria spp.|''Stephanofilaria stilesi'']]
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| − | *Occurs in cattle, buffalo, goats
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| − | *Transmitted by [[Insecta|flies]]
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| − | *Affects ventral midline (other species affect different areas of body)
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| − | *Grossly:
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| − | **Foci extending to large areas
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| − | **Errect hairs, epidermal haemorrhage, serum exudate -> crusts
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| − | *Microscopically:
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| − | **Superficial and deep perivascular dermatitis
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| − | **Eosinophils, adult and microfilarial parasites
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| − | **[[Skin Glossary - Pathology|Epidermal hyperkeratosis, parakeratosis, acanthosis]], eosinophilic microabscesses and crusts
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| − | | |
| − | ==Protozoa==
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| − | | |
| − | *Cutaneous infection may become a part of systemic infection
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| − | *Mostly caused by [[Protozoa|''Leishmania'']]
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| − | *Transmitted by [[Insecta|sandflies]]
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| − | *Occurs in dogs, cats and rodents (also humans)
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| − | *Grossly in dog:
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| − | **Generalised alopecia
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| − | **Silvery white scales
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| − | **Nodules and ulcers if more severe
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| − | **Mainly on muzzle, ears and eyes where flies feed
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| − | *Microscopically:
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| − | **[[Skin Glossary - Pathology|Hyperkeratosis, parakeratosis, crusts]]
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| − | **Granulomatous nodules in dermis
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| − | **Macrophages, some lymphocytes and plasma cells - periadnexal pattern, may affect sebaceous glands
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| − | **Organisms may be found extra or intracellularly
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