DERMATOLOGY - Ectoparasite control - LAs Flashcards Preview

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Flashcards in DERMATOLOGY - Ectoparasite control - LAs Deck (17):
1

What are the different ectoparasiticides used in large animals? 5

- Avermectins / MLs
- permethrins
- OPs
- IGRs
- synthetic pyrethroids (SPs)

2

How do avermectins/ MLs work as ectoparasiticides?

- bind to glutamate-gated chloride channel receptors
- flaccid paralysis of the pharynx
- internal and external parasites affected
- easy administrated (cf. OP dips)

3

How do permethrins work as ectoparasiticides?

- affect insect Na channels
- insect paralysis
- highly toxic in water courses

4

How do organophosphates (OPs) work as ectoparasiticides?

- AChE-R blocking
- highly toxic to all species (humans! - high PPE essential)
- Diazinon is the only UK approved active ingredient
- sheep dips

5

How do IGRs work as ectoparasiticides?

chitin synthesis interference

6

Name 2 IGRs and how they work

- CYROMAZINE - interferes with chitin synthesis
- DICYCLANIL - molting interference

7

What causes post-dipping lameness?

If using OP sheep dip, if left in bath overnight, E.rhusopathie can grow in this environment then infect next sheep through small abrasions

8

What is the only antifungal licensed for farm animals?

Enilconazole (expensive! vaccines may be more cost-effective)

9

Are OPs licensed in cattle?

No but they are licensed in sheep

10

Which ectoparasiticides are licensed in pigs?

only avermectins/ MLs

11

What ectoparasiticides are licensed in poultry?

nothing

12

What are your 3 main consideration when treating skin disease in farm animals?

- food safety
- environmental safety
- impact on other control programmes

13

Outline synthetic pyrethroids (SPs) as an ectoparasiticide

- block Na channels (nerves) --> paralysis
- there are a number of analogs
- licensed in sheep and cattle
- no other species in NOAH

14

What is the standard withdrawal time?

- Eggs/milk - 7d
- Meat - 28 d
- Double for organic farms
- Longer if vet deems necessary

15

How is sheep scab treated? 2

MLs and OPs

16

How are sheep lice treated (Bovicola or others)? 2

pyrethroids and OPs

17

How are sheep scab and sheep lice differentiated?

- Not on CS as look very similar
- Differentiate with skin sample

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