Parasites

Question 1

Common lice species and where they effect

Answer 1

• Linognathus spp.
• L. Vituli around head
• Bovicola spp.
• B. bovis (around head)

Question 2

Signs of lice infestation (Pediculosis)

Answer 2

• Asymptomatic
• Pruritus
• Excoriation
• Fleece damage and loss.
• Decreased BCS
• Severe infestations = anaemia.
• Can look similar to scab!

Question 3

Tx of pediculosis in sheep V Cattle

Answer 3

Sheep:
- Pour on pyrethroid KILLS (deltamethrin or cypermethrin)
- Oranophopshate dips = very dangerous
Treat all contacts
Also treat at start of winter housing period (with no fleece)

cattle:
- Pour on pyrethroid KILLS (deltamethrin or cypermethrin)
- Also pour on or injectable 3-ML (ivermectin, doramectin, eprinomectin)
** injectable 3MLs don’t work in sheep

Question 4

Name 4 diseases ticks can spread

Answer 4

• Louping ill (Zoonotic)
• Tickborne fever
• Tick pyaemia
• Babesia (spread by Rhipicephalus)

Question 5

what is looping ill

Answer 5

• Viral infection  encephalomyelitis  death, seizures, paralysis and death
• Most common in weaned lambs and yearlings

Question 6

what is tick borne fever

Answer 6

• Bacterium Anaplasma phagocytophilum
• Infects WBC = leucopoenia = immunosuppression.

Tx = oxytetracyline

Question 7

Signs of tick born fever

Answer 7

Pyrexia
Abortion
Infertility in males
Naive animals have severe signs

Question 8

what is tick pyaemia

Answer 8

• Immunosuppression from TBF ==> Staphylococcal infection of lambs ==> abscesses throughout body

Question 9

What causes sheep scab

Answer 9

Psoroptes.ovis mites

Question 10

What does sheep scab look like (signs and mites themselves)

Answer 10

Pruritus and wool loss

Oval shaped mites, three segmented pedicles and funnel-shaped suckers

Question 11

Tx of sheep scab

Answer 11

• Organo-Phosphate dip (Diazinon) but human health risk

ML injections (macrocyclic lactones)
- Moxidectin gives 28 days protection BUT resistance
- Doramectin (best) gives 14 days protection BUT mites last in environment 17 days so need to move to mite free pasture
- Ivermectin gives no residual protection, so need 2 injections 7 days apart and to move pasture

Question 12

Important fly species in sheep

Answer 12

Bottle fly (Calliphora spp. and Lucilla sericata)= strike or Myiasis
Nasal blot fly (Oestrus ovis) = rhinitis
head fly (Hydrotea irritans) = around horns
warble fly (hypoderma) in cattle

Question 13

where does chorioptes effect

Answer 13

bum and tail and scrotum

Question 14

where does psoroptes infect

Answer 14

ears