Skin Flashcards
Collagen defects may be genetic. There are also four dietary causes, list them
Vitamin C deficiency, Iron deficiency, Copper deficiency, sweet pea poisoning (aminoproprionitrite)
What are the ratios of scondary to primary hair in Merinos and meat sheep?
20:1 and 5:1
Which two hormones cause involution of the sebaceous glands (leading to dry coats)
Oestrogen, corticosteroids
What dermatological consequences can hyperthermia of the dam have on the offspring?
Hypertrichosis
What is the incubation period for orf
3-14 days
Described the histopathology seen with orf
Ballooning and degeneration of keratinocytes with eosinophilic intracytoplasmic viral inclusions.
What lesions are seen in malignant orf?
Non-contagious lesions on feet/legs
What is the cause of ulcerative dermatosis?
virus related to parapox
Which regions are affected in ulcerative dermatosis (3)?
Face, limbs, genitals
How does Dermatophilus congolensis appear on cytology
Gram positive branching filaments of parallel cuboidal coci (“railroad tracks”)
What agent causes fleece rot. What lesions does it cause. What areas does it affect. How is it treated?
Pseudomonas aeuruginosa. Foul, green exudative dermatitis. Back and withers. Shearing and drying
Which agents can cause malignant oedema. What toxins are involved?
Clostridium sordellii, novyi, septicum and chauvoei. Alpha-toxin and Large clostridial toxin
Which bacetria is associated with pyogranulomatous infection with sulfur granules
Actinobacillus lignieresii
What is the classic location for staphylococcla dermatitis in sheep
Above upper eyelid
Which bacteria has been decsribed as the cause of a systemic infection in a pygmy goat similar to greasy pig disease
Staphylococcus hyacus
What gram stain is Corynebacerium pseudotuberculosis? What shape is it?
Gram positive. Usually rods but can be coccoid
What proportion of UK terminal sire flocks are positive for CLA?
34%
What proportion of carcases in the UK have signs of CLA?
<1%
What are the sensitivty and specificity if the CLA ELISA?
Se 87%, spec 98%
At a prevalenec of 2% what are the sensitivity and specificity of bulk milk tan ELISA for CLA
se 73%, spec 89%
What is the sensitivity of IFNy testing for CLA?
91%
Can CLA be treated?
Closed lavage systems have been described but cullig is the sensible option.
12 weekly testing and culling for CLA for 2 years had what effect on prevalence?
Reduced from 10% to 0.4%
List most common dermatophyte pathogens of small ruminants
Trichophyton verrucosum, T. metagorphytes, Microsporum canis
Why are show breeds prediposed to ringworm?
Frequent washing strips lanolin.
Do trychophyton fluoresce?
No
What culture medium is used for ringworm
Sabouraud’s agar
Described treatment options for ringworm
Griseofulivn (ILLEGAL), Topical enilconazole, 4 times 72h apart, Topical lime sulfur - 5% daily for 7 days then weekly for a month.
What is the prevalence of lice in the UK? When do infections peak?
10-20%. Peak in winter-early spring.
List the species of lice affecting sheep (3+2)
Bovicola ovis
Linognathus ovillus
Linognathus pedalis
(Bovicola bovis)
(Bovicola caprae)
List the species of lice affecting goats (5+1)
Bovicola caprae, crassipes and limbata
Linognathus africanus and stenopsis
(Bovicola bovis)
Can lice survive off the host?
Yes for a few weeks, but epidemiologically insignificant