Skin

Question 1

Collagen defects may be genetic. There are also four dietary causes, list them

Answer 1

Vitamin C deficiency, Iron deficiency, Copper deficiency, sweet pea poisoning (aminoproprionitrite)

Question 2

What are the ratios of scondary to primary hair in Merinos and meat sheep?

Answer 2

20:1 and 5:1

Question 3

Which two hormones cause involution of the sebaceous glands (leading to dry coats)

Answer 3

Oestrogen, corticosteroids

Question 4

What dermatological consequences can hyperthermia of the dam have on the offspring?

Answer 4

Hypertrichosis

Question 5

What is the incubation period for orf

Answer 5

3-14 days

Question 6

Described the histopathology seen with orf

Answer 6

Ballooning and degeneration of keratinocytes with eosinophilic intracytoplasmic viral inclusions.

Question 7

What lesions are seen in malignant orf?

Answer 7

Non-contagious lesions on feet/legs

Question 8

What is the cause of ulcerative dermatosis?

Answer 8

virus related to parapox

Question 9

Which regions are affected in ulcerative dermatosis (3)?

Answer 9

Face, limbs, genitals

Question 10

How does Dermatophilus congolensis appear on cytology

Answer 10

Gram positive branching filaments of parallel cuboidal coci (“railroad tracks”)

Question 11

What agent causes fleece rot. What lesions does it cause. What areas does it affect. How is it treated?

Answer 11

Pseudomonas aeuruginosa. Foul, green exudative dermatitis. Back and withers. Shearing and drying

Question 12

Which agents can cause malignant oedema. What toxins are involved?

Answer 12

Clostridium sordellii, novyi, septicum and chauvoei. Alpha-toxin and Large clostridial toxin

Question 13

Which bacetria is associated with pyogranulomatous infection with sulfur granules

Answer 13

Actinobacillus lignieresii

Question 14

What is the classic location for staphylococcla dermatitis in sheep

Answer 14

Above upper eyelid

Question 15

Which bacteria has been decsribed as the cause of a systemic infection in a pygmy goat similar to greasy pig disease

Answer 15

Staphylococcus hyacus

Question 16

What gram stain is Corynebacerium pseudotuberculosis? What shape is it?

Answer 16

Gram positive. Usually rods but can be coccoid

Question 17

What proportion of UK terminal sire flocks are positive for CLA?

Answer 17

34%

Question 18

What proportion of carcases in the UK have signs of CLA?

Answer 18

<1%

Question 19

What are the sensitivty and specificity if the CLA ELISA?

Answer 19

Se 87%, spec 98%

Question 20

At a prevalenec of 2% what are the sensitivity and specificity of bulk milk tan ELISA for CLA

Answer 20

se 73%, spec 89%

Question 20

What is the sensitivity of IFNy testing for CLA?

Answer 20

91%

Question 20

Can CLA be treated?

Answer 20

Closed lavage systems have been described but cullig is the sensible option.

Question 21

12 weekly testing and culling for CLA for 2 years had what effect on prevalence?

Answer 21

Reduced from 10% to 0.4%

Question 22

List most common dermatophyte pathogens of small ruminants

Answer 22

Trichophyton verrucosum, T. metagorphytes, Microsporum canis

Question 23

Why are show breeds prediposed to ringworm?

Answer 23

Frequent washing strips lanolin.

Question 24

Do trychophyton fluoresce?

Answer 24

No

Question 25

What culture medium is used for ringworm

Answer 25

Sabouraud's agar

Question 26

Described treatment options for ringworm

Answer 26

Griseofulivn (ILLEGAL), Topical enilconazole, 4 times 72h apart, Topical lime sulfur - 5% daily for 7 days then weekly for a month.

Question 27

What is the prevalence of lice in the UK? When do infections peak?

Answer 27

10-20%. Peak in winter-early spring.

Question 28

List the species of lice affecting sheep (3+2)

Answer 28

Bovicola ovis Linognathus ovillus Linognathus pedalis (Bovicola bovis) (Bovicola caprae)

Question 29

List the species of lice affecting goats (5+1)

Answer 29

Bovicola caprae, crassipes and limbata Linognathus africanus and stenopsis (Bovicola bovis)

Question 30

Can lice survive off the host?

Answer 30

Yes for a few weeks, but epidemiologically insignificant

Question 31

How long do louse eggs take to hatch?

Answer 31

1-2 weeks

Question 32

Howlong do lice take to develop to adults?

Answer 32

2-4 weeks

Question 33

How long post-infection is alopecia commonly seen with louse infestations?

Answer 33

5 weeks

Question 34

How can lice be treated? Can these be used in lactating animals

Answer 34

Deltamethrin (lasts 5 weeks) - no, Cypermethrin (lasts 8-12 weeks) - no, eprinomectin (injectable for sucking, pour-on for biting) - yes

Question 35

Is louse resistance heritable? What beed was this studied in?

Answer 35

Yes - Romney

Question 36

Describe the microscopic appearance of Psooptes ovis

Answer 36

Elongated head, Firts pair of legs jointed. First two pairs of legs have 3-segmented pedicles with funnel-shaped suckers.

Question 37

How long is the intergenerational interval of Psoroptes of ovis?

Answer 37

11-19 days.

Question 38

For how long are Psoroptes ovis infectious off the host?

Answer 38

15-16 days

Question 39

How soon after infection can the sheep scab ELISA be used? What is its sensitivity and specificity?

Answer 39

2 weeks. 98% se, 96% sp

Question 40

How long do diazinon dip and moxidectin 2% persist against sheep scab? Can they be used in milk sheep?

Answer 40

63 days and 60 days. No, have to use repeated eprinomectin treatments.

Question 41

What experimental vaccine is there against sheeo scab? How effective is it?

Answer 41

7 subunit cocktail vaccine, reduces clinical signs and mite numbers but not sterile immunity.

Question 42

Describe the appearance of sarcoptes scabei

Answer 42

ROund head. Long non-jointed pedicles.

Question 43

How long is sarcoptes scabei life-cycle?

Answer 43

10-17 days

Question 44

Described the lesion distribtuion for sarcoptic mange

Answer 44

face and non-wooled areas in sheep. Generalised in goats

Question 45

How is sarcoptic mange treated?

Answer 45

Ivermectin injection every 7 days.

Question 46

Which species cause chorioptic mange? Describe their appearance

Answer 46

Chorioptes ovis and caprae. Short unsegmented pedicles, oval body.

Question 47

What are the prediliction sites for chorioptes?

Answer 47

Scrotum, lower limbs

Question 48

How long is the chorioptes life cycle? How long can they presist off-host?

Answer 48

2-3 week life ycle. A few days survival off host

Question 49

Hich bacteria is secondarily associated with chorioptic mange? Are there any other secondary effects of chorioptic ange

Answer 49

Staphylococci. Heat -> temporary ram infertility

Question 50

How is chorioptic mange treated

Answer 50

Topical eprinomectin - paint on to lesions to maxmise concentrations. Fipronil effective but illegal.

Question 51

How many demodex species infect small ruminants?

Answer 51

Two - ovis and caprae

Question 52

How is demodecosis treated?

Answer 52

Repeated macrocyclic lactones or weekly amitraz baths (10-12 weeks treatment reqd for both).

Question 53

Which two fly species are associated with flystrike in most of Europe? Which species is present in Eastern Europe, Spain and Greece, and how does it's pathology differ?

Answer 53

Lucillia sericata and Protphormia terranovae. Wohlfahrtia magnifica - more aggressive, focuses on anus/genitals.

Question 54

How do Lucilia sericata penetrate the skin?

Answer 54

Proteolytic enzymes and mouth hooks

Question 55

How long do flystrke larvae infect the host before pupating?

Answer 55

4-5 days

Question 56

What proportion of farms in the UK and Netherlands are affected by fly strike annually?

Answer 56

UK: 75%. NL: 50%

Question 57

Describe the treatment options and duratiosn for flystrike

Answer 57

Cypermethrin 6-8 weeks Alpha-cyperpethrin 8-10 weeks Deltamethrin no persistence Cyromazine - 9 weeks Dicyclinil - 16 weeks+ Diazinon - 6 weeks

Question 58

Has drug resistant fly strike been reported in Europe?

Answer 58

No but permethrin resistance reported in L. cuprina in Australia and IGR resistance shown in lab.

Question 59

Which biological control options have been proposed for flystrike? Are they effective?

Answer 59

Bacillus thurigiensis and various entomopathogenic fungi. Limited duration effect in lab studies. Tea tree oil is an effective repellant in the housed sheep but not clear how it persists in rain etc.

Question 60

How effective are fly traps for flystrike?

Answer 60

1 synthetic-baited trap per 100 sheep can reduce fly populations 60%. Liver-baited sticky paper shown to reduce flystrike in SW England 80%. However non-specific offal baited traps may kill competitors and increase Lucillia populations.

Question 61

Name the main two species of small ruminant ear mite. For what bacteria might they act as a vector?

Answer 61

Psoroptes cuniculi and Raillietia caprae. Mycoplasma spp.

Question 62

What is the latin name for the sheep ked. Which notifiable disease can they act as a vector for?

Answer 62

Melophagus ovinus. BTV

Question 63

Which parasite can cause hide damage in goats in Mediterranean countries

Answer 63

Goat warble fly (Przhevalskiana silenu)

Question 64

Against what antigen is the type-ii hypersenstivity reaction medaited in Pemphigous Foliaceous?

Answer 64

Keratinocyte glycocalyx

Question 65

What is seen on histopathology in Pemphigus Foliaceus?

Answer 65

bilsters, acantholytic keratinocytes

Question 66

Name the endophyte that causes fescue toxicity. What are the dermatological signs?

Answer 66

Epichloe coenophialum. Vascular constriction leading to necrosis of extremities, especially in winter.

Question 67

Which two mineral deficiencies are associated with poor quality hair/wool?

Answer 67

Copper, Iodine

Question 68

What are the signs of zinc deficiency?

Answer 68

Parakeratosis, wrinkled skin, swollen hocks, alopecia, dental pad overgrowth, small testes.

Question 69

Excesses of which minerals can lead to zinc deficiency?

Answer 69

Calcium and Phspshorous

Question 70

What are the signs of vitmain A deficiency? What feedstuff predisposes?

Answer 70

Hair loss, bight blindness, overgrown hooves, corneal ulceration. Hay stored for a long time

Question 71

Name two primary photosensitizing toxins

Answer 71

Phyloerythrin. Hypericin (St John's Wort)

Question 72

Which fungus causes secondary photosensitization (facial eczema). What is the toxin? What is the pathology?

Answer 72

Phythomyces chartarum Sporedesmin Biliary fibrosis and duct occlusion

Question 73

Name three plant/algal causes of secondary photosensitization

Answer 73

Pyrrolizidine alkaloid plants (ragwort, heliotrope) Bluegreen algae Bog asphodel (Narthecium ossifragum)

Question 74

Name three sheep breeds with inherited photosensitization

Answer 74

Southdown, Corriedale, Santa-Ines

Question 75

Name two breeds of sheep with an inherited collagedn dysplasia

Answer 75

Norwegian and White Dorper

Question 76

Which type of collagen is lacking in Epidermolysis bullosa / Epitheliogenesis imperfecta cases?

Answer 76

Type VII collagen

Question 77

Which sheep breeds have heritable epidermolysis bullosa / epthitheliogenesisimperfecta

Answer 77

Weisses Alpenschaf, Suffolk, South Down

Question 78

Which gene is assocaited with eptheliogenesis imperfecta in sheep. Which layer of the skin is affected? Which layer can also be affected by an unknown mutation in sheep and goats

Answer 78

LAMC2 frame shift Lamina Lucida Sublamina Densa

Question 79

Which breed of sheep has an inherited hypotrichosis?

Answer 79

Dorsets