Skin/wool/hair disorders Flashcards
Diseases associated with pruritis (10)
- Scrapie S/G
- Sheep scab (psoroptic mange)
- Sarcoptic mange G
- Chorioptic mange S/G
- Culicoides hypersensitivity S
- Lice S/G
- Keds S
- Blowfly S
- Headfly
- Pemphigus foliaceous
Scrapie
Prion, TSE
PrP gene determines susceptibility
Latency in lympho-reticular system
Zoonotic risk
Wild, excitable, high stepping gait, hind leg ataxia, abnormal posture, pruritis, etc.
Emaciated with loss of fleece - ragged
Diagnose by staining for PrP-sc in tonsil biopsy
No treatment
Sheep scab (psoroptes ovis)
Papules which exude serous fluid, followed by extensive serous exudate and wool loss
Abscesses and seromas may form
Rubbing, biting, and scratching
Alopecia
Epileptiform fits and/or death may occur
It is an allergic reaction to mite faecal antigen
Dip in OP twice yearly or as treatment when needed
Notifiable
Ear mange (psoroptes)
Two different psoroptes populations
Psoroptes cuniculi usually causes ear mange, but can be Ps ovis
Ear shaking, ear rubbing, aural haematomas, chronic fibrosis
Diagnose by identifying mites in the aural cavity
Treat with systemic avermectins
Chorioptic mange
Chorioptes ovis/caprae
Exudation on haired areas, often asymptomatic though
Stamping feet, biting at legs, alopecia, thickening of scrotum and inguinum
Control with dip or spray acaricide
Chorioptic mange
Chorioptes ovis/caprae
Exudation on haired areas, often asymptomatic though
Stamping feet, biting at legs, alopecia, thickening of scrotum and inguinum
Control with dip or spray acaricide
Sarcoptes mange
Sarcoptes scabei
Hair loss around eyes and ears, erythema and nodules
Skin thickening and wrinkling
Intense pruritis and scratching, loss of condition, reduced milk production
Treat with avermectin or OP wash
Culicoides hypersensitivity
Midges are vectors of bluetongue and schmallenburg
Papules, crusting, alopecia
Alopecia of haired areas especially ears, ventrum, and perineum, rubbing of lesions
Skin test with midge antigen
House at dawn and dusk, insecticidal ear tags etc.
Treat with corticosteroid cream
Harvest mite
Neotrombicula autumnalis
Pruritis and hair loss on face, ventrum and lower limbs seen in late summer/autumn
Orange mites on skin, rarely seen on animals in the daytime
Lice treatments kill mites but harvest mites are killed by first frost, need environmental treatment
Lice
Chewing and sucking lice
Hypersensitivity
Pruritis, tagging of the wool and anaemia esp of sheep in low BCS
Seen during the winter
Control by improving BCS, OP dip for sheep
For goats use avermectins or pour on synthetic pyrethroids
Lice general
Chronic
Wool grazed
Irritated
Mortality is rare
Diffuse scaly scab
No definite point of origin
Scab general
Acute
Wool loss
Intense irritation
Mortality is common
Definite crusty scab
Definite point of origin
Flies general
Permanent (entire lifecycle on host)
Semi-permanent (Part of lifecycle on host)
Parasitic (blood feeding, biting, secretophagous)
KEDS (malophagous ovinus)
A flightless fly, larvae laid directly onto sheep
Obligate permanent parasites
Blood sucking and hypersensitivity reaction in wooled areas
Anaemia and weight loss
Control by shearing and dipping
Myiasis/blow fly strike
Lucillia sericata (primary strike), Phormia terra-novae (primary strike), Calliphora erythrocephala (secondary strike)
Primary flies lay eggs in soiled fleece and the larvae lacerate the skin
Secondary fly larvae attack already damaged skin
Epidemic of strike occurs after hot dry weather, eggs hatch within 24hrs
Exudate forms wet wounds that attracts more flies
Death in severely affected sheep - lipid soluble ammonia in larvae faeces
Tail swishing, restlessness, anorexia, foul smell, presence of maggots
OP dip, synthetic pyrethroid pour on for control
Clip, flush with peroxide/chlorhexidine, systemic ABs
Guarded prognosis
