Ectoparasites

Question 1

Name a chewing louse seen in sheep

Answer 1

Bovicola ovis

Question 2

Name some environmental risk factors for Bovicola ovis infestation

Answer 2

Warm, dry weather

Dark housing

Question 3

How is Bovicola ovis treated? Do all sheep need treating?

Answer 3

Deltamethrin (synthetic pyrethroid pour-on)
Or diazinon dip (OP)
Treat all if indoors, treat worst affected if outdoors

Question 4

Which mites are found on the ventral abdomen and scrotum, causing pruritis and infertility?

Answer 4

Chorioptes bovis

Question 5

What is the treatment for Chorioptes bovis?

Answer 5

OP dip (diazinon)

Question 6

How is Chorioptes bovis diagnosed?

Answer 6

Skin scrape

Question 7

What flies cause Flystrike?

Answer 7

Lucillia sericata

Question 8

When does Flystrike typically occur?

Answer 8

May-October

Question 9

Name some risk factors for flystrike

Answer 9

Faecal soiling on wool
Warm, humid temperatur
Carcasses on farm (attract flies)

Question 10

What is the treatment for flystrike and headflies?

Answer 10

Deltamethrin (synthetic pyrethroid)
Or diazinon (OP dip)
Insect growth regulators
Clean wounds
Supportive care

Question 11

How can headflies and flystrike be prevented?

Answer 11

Shearing
Dagging
Tail docking
Fly and other parasite control

Question 12

What fly in sheep affects the base of the the horns?

Answer 12

Headfly - Hydrotea irritans

Question 13

What are the clinical signs of Hydrotea irritans in sheep?

Answer 13

Affected horn base

Occular discharge

Question 14

Ovine sweet itch is uncommon. What is sweet itch?

Answer 14

Hypersensitivity to Culicoides midges

Question 15

What causes Sheep Scab?

Answer 15

Psoroptes ovis mites

Question 16

When is Sheep Scab more prevalent?

Answer 16

Autumn, Winter months

Question 17

Sheep Scab may cause an allergic reaction to the site 6-8 weeks post-infection. Where on the body are Psoroptes predisposed to?

Answer 17

Flanks
Dorsum
(or whole sheep)

Question 18

How can Sheep Scab be diagnosed?

Answer 18

Wool pluck or skin scrape from edge of lesion

ELISA - (requires 12+ sheep)

Question 19

What is the treatment for sheep scab? How much of the flock should be treated?

Answer 19

Diazinon (OP dip)
Ivermectin, moxidectin (MLs)
Dexamethasone if severe/allergic reaction
ALL of flock

Question 20

What is the treatment for all sheep ectoparasites?

Answer 20

Diazinon - OP dip
Deltamethrin - SP pour on
(and ivermectin +/- dexamethasone for Sheep Scab)

Question 21

Give examples of vectors that spread tick-borne diseases

Answer 21

Ixodes ricinus
Dermacentor reticulata
Haemphyllis punctuate

Question 22

Extra-care should be taken with which stock around tick-borne diseases?

Answer 22

Young, naive stock

Give oxytetracycline before going into tick area

Question 23

What is the treatment for ticks in sheep?

Answer 23

Diazinon (OP dip)

Deltamethrin (SP pour-on)

Question 24

Louping ill is caused by which virus and is spread in which seasons?

Answer 24

Flavivirus

Spring, Summer, Autumn

Question 25

How can louping ill be prevented?

Answer 25

Tick prevention

Vaccine

Question 26

What pathogen causes the tickborne diseaes Q-fever?

Answer 26

Coxiella burnetti

Flu symptoms in humans

Question 27

What pathogen causes tick-borne fever? Do animals develop immunity to this?

Answer 27

Analasma phagocytophilia

Yes develop immunity - naive animals susceptible

Question 28

Which Tickborne disease is most common in Autumn and causes profound immunosuppression, fever, infertiliy in rams and abortion in ewes?

Answer 28

Tickborne Fever

Anaplasma phagocytophilia

Question 29

What pathogen causes tick pyaemia?

Answer 29

Staph aureus

Question 30

What does tick pyaemia (Staph aureus) cause in lambs?

Answer 30

Polyarthritis/joint ill

Spinal abscesses