Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Small Ruminants > Skin diseases in sheep > Flashcards

Skin diseases in sheep Flashcards

1
Q

How do sheep get scrapie

A

Mainly via placental transmission
Some horizontal transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Symptoms of scrapie in sheep

A

Hind limb, high stepping gait, wild/excitable, pruritis (with wool loss), emaciation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do we confirm scrapie diagnosis

A

Brainstem testing; THEN MUST REPORT AS NOTIFIABLE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the cause and symptoms of chorioptic mange

A

From mite Chorioptes bovis
> Often asymptomatic: lesions on base of tail, perineum,, udder, scrotum, lower limbs, hooves, ears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the cause of sheep scab

A

= Ovine psoroptic mange
> From Psoroptes ovis
- Used to be notifiable
Spread mainly sheep to sheep but can survive in environment for 3 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Symptoms of sheep scab

A

Wool loss and formation of progressive scab lesions
Lesions expand from subclinical to clinical as mite numbers increase; find mites at edges of lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Detecting sheep scab

A

Look for reaction to massaging the lesion
- Ranges from slight reflex to epileptiform fit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What two mites can cause problems in the ear

A

1) Psoroptes ovis; in sheep scab cases
2) Psoroptes cuniculi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Differences between scab and lice in sheep

A

Scab is more acute, more intense irritation, wool loss, mortality higher, crusty scabs with definitie point of origin

Whereas live: more chornic, irritation less intense, rare to get mortality, no definitive point of origin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Treating sheep scab/lice

A

Organophosphate dips = gold standard

Synthetic pyrethroid spot ons are good for chewing lice but not good for sheep sca

Can use macrocyclic lactones: e.g moxidectin; BUT don’t do every year because of resistance risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which chewing lice species affects sheep and which sucking

A

Chewing = Bovicola ovis
Sucking = Linognathus ovillis, pedalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is an example of a permanent fly i.e whole life cycle on host

A

Keds = Hippoboscid flies
e.g melophagus ovinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What diseases can biting midges transmit

A

Schamellenberg virus; bluetongue virus
+ can cause bite allergies in hosts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What type of fly is the head fly; hydrotaea irritans

A

Secretophagous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does myiasis mean

A

The infestation of living tissue by larvae of true flies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Example of an obligate and facultative agent of myiasis

A

Obligate = oestrus ovis (nasal bot fly)
Facultative = lucilla seratus; sheep blow fly strike

17
Q

How does sheep blow fly strike work

A

Lucilla sericata flies are attracted to odours from sheep; lay eggs mainly on tail head
- Larvae need >70% moisture; hatch and migrate down to breech skin and use hooked mouthparts and salivary secretions to eat into in
> Exudate from wound wets the wool and creates an odour that attracts MORE FLIES

18
Q

What is the cause of death from sheep blow fly strike

A

Waste products of the larvae
= lipid soluble ammonia which is absorbed by skin into blood; bypasses normal detoxification
-> Get organ damage

19
Q

How can we treat sheep blow fly strike

A

Clip wool
Clean wound to remove larvae and waste products
Give synthetic pyrethroids and avermectin to make animal TOXIC
+ antibiotics and NSAIDs

20
Q

How do triazine derived IGRs work

A

e.g Cyromazine
> Via interference with moulting and pupation

21
Q

How do pyrimidine derived IGRs work

A

e.g Dicyclanil
> Via interference with chitin metabolism

22
Q

Life cycle of sheep keds (melophagous ovinus)

A

Obligate permanent parasite
> wingless blood sucking flies; eggs and larvae develop WITHIN THE FEMALE; so L3 pupate directly after deposition and attach to wool; then emerge in 2 weeks

23
Q

Control of ticks two products

A

OPs (organophosphates)
SPs (synthetic pyrethroids)

24
Q

Cause of contagious pustular dermatitis (orf)

A

a parapox virus

25
Q

Pathogenesis of orf

A

Lesions on lips of lambs and udders of ewes
= papular crusting lesions; progressing to vesicles and pustures

Can give live vaccines to ambs from 1 day old (BUT DON’T GIVE UNLESS FARM HAS ORF ALREADY AS IT IS A LIVE VACCINE AND WILL GET IT FOREVER)

26
Q

What bacteria causes fleece rot

A

Pseudomonas

27
Q

What is big head

A

Clostridial cellulitis

28
Q

Primary and secondary causes of photosensitisation in sheep

A

Primary = via photodynamic agents e.g St John’s wort
Secondary = via liver damage e.g from pog asphodel or liver disase

29
Q

What metal deficiency can cause skin disease

A

Zinc

30
Q

What is wool slip

A

Where high cortisol release in response to stress causes partial or complete wool loss a few weeks later due to breakage

Small Ruminants (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions