Farm Animal Skin Disease

Question 1

What are the major chemical groups used for treatment of sheep, cattle and pigs?

Answer 1

Macrocyclic lactones
Synthetic pyrethroids
Organophosphates
Insect growth regulators

Question 2

Give an example of a macrocyclic lactone

Answer 2

Ivermectin

Question 3

Give examples of synthetic pyrethroids

Answer 3

Cis cypermethrin

Deltamethrin

Question 4

Give an example of an organophosphate…

Answer 4

Diazinon

Question 5

Give an example of an insect growth regulator…

Answer 5

Cyromazine

Question 6

Why are organophosphates being phased out of use?

Answer 6

Effects on wildlife

Question 7

What are the two lice of sheep and do they chew or suck?

Answer 7

Bovicola ovis - sucking

Linognathus ovillus - chewing

Question 8

Why has the incidence of sheep body lice infestation in the UK increased recently?

Answer 8

Dipping has stopped

Question 9

Outline the clinical signs associated with sheep body lice…

Answer 9

Severe fleece derangement

Rubbing/biting wool

Question 10

Outline the epidemiology of the sheep body louse…

Answer 10

Numbers increase in long wool
Decline dramatically at shearing
Reduced by solar radiation

Question 11

How are sheep body lice diagnosed?

Answer 11

Part of the wool and examine near skin

Question 12

How are sheep body lice treatment?

Answer 12

Shearing
Insecticides
- Pour ons (deltamethrin)
- Saturation dip (organophosphates, synthetic pyrethroids)

Question 13

List of mites of sheep…

Answer 13

Sarcoptes scabei 
Demodex ovis
Psorobia ovis
Chorioptes bovis
Psoroptes ovis

Question 14

What is sheep scab?

Answer 14

Psoroptic manage

Question 15

Outline the clinical signs associated with psoroptic mange…

Answer 15

Pustules, then spreading moist lesions
Matted fleece
Extreme pruritus 
Mites just visible with naked eye
Sheep may become thin and die

Question 16

Outline the epidemiology of psoroptic mange…

Answer 16

Winter more favourable
Infections may be latent over summer
Mites can multiple rapidly

Question 17

Outline techniques available for treatment and control of psoroptic mange…

Answer 17

Plunge dipping (organophosphate solution)
Macrocyclic lactone injections

Question 18

For how long may pastures, fences, buildings etc remain a source of psoroptes re-infection?

Answer 18

15 days

Question 19

Why might plunge dipping not be effective for treatment of psoroptic mange?

Answer 19

Treatment times too short
Heads not dipped
Dip heavily fouled
Strength too low

Question 20

What is blowfly strike?

Answer 20

Cutaneous myiasis

Question 21

Outline the pathogenesis of blowfly strike…

Answer 21

Primary flies lay eggs in moist wool and inflamed skin
Larvae feed on the skin surface and cause extensive skin damage
Toxaemia due to skin necrosis and absorption of bacterial toxins
Subsequent invasion by secondary/tertiary flies

Question 22

What are the predilection sites for blowfly strike?

Answer 22

Head (base of horns)
Breech
Prepuce
Body
Wounds

Question 23

Outline the treatment for blowfly strike…

Answer 23

Clip surrounding area
Clean tissues and remove visible maggots
Apply insecticides
Supportive treatment indicated in severe cases

Question 24

Outline the options available for prevention of blowfly strike…

Answer 24

Tail docking
Cyromazine
Dicyclanil
Cypermethrin

Question 25

List the live of cattle

Answer 25

Bovicola bovis Linognathus vituli Haematopinus eurysternus Solenopotes capillatus

Question 26

How does chorioptes bovis cause infertility in rams?

Answer 26

Inflames scrotum leading to increased temperature

Question 27

Outline the clinical signs of lice in cattle...

Answer 27

Number increase in cool months Peak in early spring Decline with coat shedding, solar radiation, and higher temperature Most common in housed cattle

Question 28

Outline diagnosis of lice in cattle...

Answer 28

Visible to the naked eye | Species distinguished by microscope

Question 29

When is the best time to treat cattle for lice?

Answer 29

Autumn

Question 30

Outline the treatments for lice in cattle...

Answer 30

Macrocyclic lactones - Kills all sucking lice - Reduces bovicola bovis Others: - Deltamethrin - Cypermethrin

Question 31

List the mites found in cattle...

Answer 31

Sarcoptes sabiei Chorioptes bovis Demodex bovis Psoroptes ovis

Question 32

Describe chorioptic mange in cattle...

Answer 32

Tail, hind legs, udder, perineum Very common, mostly in housed cattle Pruritic Not severe

Question 33

Describe sarcoptic mange in cattle...

Answer 33

``` Causes head and tail mange Mostly in housed cattle Any age affected Can be severe and acute Transmission by direct contact and fomites ```

Question 34

How is sarcoptic mange in cattle diagnosed?

Answer 34

Clinical signs Skin scraping Skin biopsy

Question 35

How is sarcoptic mange treated in cattle?

Answer 35

Macrocyclic lactones

Question 36

Outline treatment for psoroptic mange in cattle...

Answer 36

Permethrin pour-on

Question 37

Describe demodectic mange in cattle...

Answer 37

Common, but rarely diagnosed More a problem for hide image No pruritus, little hair loss Occasionally develops into nodules and secondary infection

Question 38

What is lumpy wool?

Answer 38

Dermatophilosis in sheep

Question 39

In what species does dermatophilosis occur?

Answer 39

``` Sheep Camelids Goats Pigs Horses (Cattle) ```

Question 40

Describe dermatophilosis

Answer 40

Produces crusts of varying thickness on wooled/haired skin Lesions can be painful to lift off Tends to follow wet weather

Question 41

How is dermatophilosis diagnosed?

Answer 41

History Clinical signs Smears from scabs

Question 42

How is dermatophilosis treated?

Answer 42

``` Remove animals from wet conditions Correct any underlying problems predisposing to infection Systemic ABs Topical treatment (Chlorhexidine) ```

Question 43

What is ringworm?

Answer 43

Dermatophytosis

Question 44

Describe ringworm

Answer 44

``` Focal patches of thick grey crust/scales with alopecia Particularly affects head and neck Pruritus variable Self-limiting Zoonotic ```

Question 45

Outline treatment and control for ringworm..

Answer 45

Enilconazole | Vaccinations