ectoparasiticides

Question 1

examples of chemical controls for dogs

Answer 1

spot-ons
chewable tablets
Collars
Environmental
Injectable

Question 2

examples of chemical control for livestock

Answer 2

Ear tags (cattle)
Pour-ons
Spot-ons
Injectable
Dip
Oral e.g. drinking water
(poultry

Question 3

chemical control examples for horses

Answer 3

Sprays
Pour-ons
Ora

Question 4

major classes of ectoparasiticides

Answer 4

organochlorines
organophosphates
synthetic pyrethroids
macrocyclic lactones
neonicotinoids
phenylpyrazole
isoxazolines
bispyrazoles
formamidine
insect growth regulators

Question 5

example of organochlorines

Answer 5

DDT
- highly toxic
= bioaccumulation, food chain, immune impairment

Question 6

example of organophosphates

Answer 6

diazinon

Question 7

delivery of organophosphates and which animal are they only used for

Answer 7

plunge dip
sheep

Question 8

mode of action of organophosphates

Answer 8

acetylcholine released from insect nerve ending - OPs bind to AChe, (enzyme which inactivates ACh) acytyl choline builds up = paralysis

Question 9

safety of organophosphates

Answer 9

lipid soluble
highly toxic to humans

Question 10

examples of synthetic pyrethroids

Answer 10

permethrin
cypermethrin
deltamethrin

Question 11

delivery of SPs

Answer 11

ear tags
pour on
spray
spot - on
collars

Question 12

targets of SPs

Answer 12

flies
lice
ticks

Question 13

targets of organophosphates

Answer 13

blowfly
lice
ticks
mites
keds

Question 14

mode of action of SPs

Answer 14

excites cell membranes by maintaining depolarisation
Na channels stay open
= paralysis

Question 15

safety of SPs

Answer 15

repellency and rapid kill
not residual
low mammalian toxicity

Question 16

contradictions of SPs

Answer 16

permethrin toxic to cats.

Question 17

examples of MLs

Answer 17

ivermectin
doramectin
selamectin

Question 18

delivery of MLs

Answer 18

IM or SC injection
spot on
pour on

Question 19

targets of macrocyclic lactones

Answer 19

broad spectrum
mites
lice
bots
warbles
fleas

Question 20

mode of action of ML

Answer 20

stimulate GABA release from nerve endings
enhances binding to its receptor in post-synaptic neurone membrane
- increases flow of Cl = hyperpolarisation - paralysis

Question 21

safety of MLs

Answer 21

safe
GABA neurotransmission confined to CNS in mammals - large molecules do not readily cross blood-brain barrier

Question 22

contradictions of MLs

Answer 22

collies sensitive to ivermectin due to mdr1 gene
long meat and milk withdrawal

Question 23

example of neonicotinoid

Answer 23

imidacloprid

Question 24

delivery of imidacloprid

Answer 24

spot-on

Question 25

targets of imidacloprid

Answer 25

fleas - dog, cat, rabbits T. canis - biting lice

Question 26

mode of action of imidacloprid

Answer 26

binds to nicotinic ACh receptors in insect nervous system - paralysis

Question 27

safety of imidacloprid

Answer 27

toxic to aquatic invertebrates, bees restricted in agricultural use in EU

Question 28

example of phenylpryazole

Answer 28

fipronil

Question 29

delivery of fipronil

Answer 29

spot-on, spray

Question 30

targets of fipronil

Answer 30

fleas, ticks

Question 31

mode of action of fipronil

Answer 31

blocks GABA transmitter - paralysis

Question 32

safety of fipronil

Answer 32

toxic to fish and bees Lipophilic, diffuses into sebaceous glands of hair follicles which act as a reservoir = long residual activity

Question 33

example of a formamidine

Answer 33

amitraz

Question 34

delivery of amitraz

Answer 34

wash impregnated strips

Question 35

targets of amitraz

Answer 35

demodectic mange in dogs

Question 36

mode of action of amitraz

Answer 36

interacts with octopamine receptors = hyperexcitation = paralysis

Question 37

safety of amitraz

Answer 37

some dogs sensitive

Question 38

contradictions of amitraz

Answer 38

toxic to horses and cats

Question 39

examples of isoxazolines

Answer 39

fluralaner afoxolaner lotilaner

Question 40

delivery of isoxazolines

Answer 40

chewable tablets spots on injectable oral prep for drinking water in poultry

Question 41

targets of isoxazolines

Answer 41

fleas ticks mites

Question 42

mode of action of isoxazolines

Answer 42

GABA AND glutamate receptor ANTAGONIST = acts on Cl channel in neurone synapses = paralysis

Question 43

safety of isoxazolines

Answer 43

safe although environmental/invertebrate toxicity not fully established

Question 44

novelty of isoxazolines

Answer 44

Fluralaner and afoxolaner kill fleas within 8 hours and ticks within 48 hours. Active for 3 months. Lotilaner kills fleas within 2 hours and ticks within 12 hours = can prevent Borrelia and Babesia transmission

Question 45

example of bispyrazoles

Answer 45

tigolaner - newer drug licensed in cats

Question 46

delivery of tigolaner

Answer 46

spot - on

Question 47

targets of tigolaner

Answer 47

fleas ticks mites

Question 48

mode of action of tigolaner

Answer 48

GABA and glutamate receptor antagonist (acts on the Cl- channel in neurone synapses) = paralysis

Question 49

safety of tigolaner

Answer 49

Safe, although environmental/invertebrate toxicity not fully established.

Question 50

two groups of insect growth regulators

Answer 50

chitin inhibitors juvenile hormone analogues

Question 51

example of chitin inhibitors

Answer 51

Cyromazine, Dicyclanil, Diflubenzuron, Lufenuron

Question 52

delivery of chitin inhibitors

Answer 52

spot on injection pour on

Question 53

targets of chitin inhibitors

Answer 53

blowflies fleas

Question 54

mode of action of chitin inhibitors

Answer 54

Chitin inhibitor, prevents egg hatch and moulting. Cyromazine protects against blowflies for ~14w

Question 55

Juvenile hormone analogues example

Answer 55

methoprene

Question 56

delivery of Juvenile hormone analogues

Answer 56

spot-on

Question 57

targets of Juvenile hormone analogues

Answer 57

fleas

Question 58

mode of action of Juvenile hormone analogues

Answer 58

Mimics the prohormone ecdysone which keeps fleas young

Question 59

which causes GABA paralysis

Answer 59

MLs - stimulate GABA release phenylpyrazole - blocks GABA transmitter isoxazoline and bspyrazole - GABA AND GLUTAMATE ANTOGINIST

Question 60

which causes ACh paralysis

Answer 60

OP - AChE inhibitor neonicitinoid - binds to ACh receptor

Question 61

what causes other paralysis

Answer 61

SPs - Na channels open formamidine - acts on octopamine receptors