Ecto-parasites

Question 1

Ectoparasiticide formulations

Answer 1

-ear tags
-collars
-immersion baths
-topical dusts
-shampoos
-premises application
-pour on

Question 2

Organophosphates

Answer 2

Acetylcholinesterase inhibitors
-irreversible binding to AChE
-highly toxic to mammals (muscarinic first, then nicotinic; delayed neuropathy) and environmental concerns

eg. diazinon ear tags for horn and face flies

Question 3

Carbamates

Answer 3

-acetylcholinesterase inhibitors- competitive inhibitors
-toxic (not as much as organophosphates)

eg. carbaryl dusting powder for control of mites, fleas, lice, ticks, flies

Question 4

Pyrethrins/Pyrethroids

Answer 4

Pesticides:
‘thrins’=chrysanthemum plants
‘throids’= synthetic

*highly lipid soluble; stay in stratum corneum; no systemic absorption

Used for fleas, ticks, flies, lice, some mite activity

Question 5

Pyrethrins/Pyrethroids mechanism

Answer 5

-Act on Na channels making them stay open OR other neurotransmitter functions

Question 6

Pyrethrins/Pyrethroids formulations

Answer 6

-shampoos, sprays, dips, dusts, ear tags

eg. CyLence

Question 7

Pyrethrins/Pyrethroids toxicity in cats

Answer 7

-may be due to grooming or topical products or poor hepatic glucuronidation

**also toxic to fish

Question 8

Neonicotinoids

Answer 8

-like nicotides but more stable
-non ionized at physiological pH so crosses blood brain barrier
-works on INSECT nicotinic receptors (no effect on vertebrates) depolarizing (Na open) then stops neural transmission
-environmental impact on bees

Question 9

Imidacloprid

Answer 9

-neonicotinoids
-generally safe
-minimal transdermal absorption, but surface translocation
-kills adult and larval fleas and lice (limited to ticks because they aren’t on animal for long)

eg. topical formulations for dogs and cats= advantage/advantix

Question 10

Nitenpyram

Answer 10

-neonicotinoids
-capstar; oral tablet for flea adults of dogs and cats
-need to give daily if fleas present

Question 11

Insect growth regulators

Answer 11

Pyriproxifen!
-analogues of hormones which regulate insect larval development
*no effect on adult insect
=leads to arrested development (but does not clear infection so best to mix with other product)

-little toxicity
-slow because only acts on larvae

Question 12

Insect development inhibitors

Answer 12

-block development of insec exoskeleton by inhibiting chitin synthesis or utilisation
*controls fleas at egg and larval stages

Question 13

LuFEnuron

Answer 13

-insect development inhibitor, inhibiting chitin

eg. Sentinel for dogs
eg. Program for cats
eg. aquaculture use for sea lice

Question 14

Isoxazoline (Laner)

Answer 14

-antagonists of GABA and glutamine gated Cl channel resulting in lack of hyperpolarization so excess neural activity

-used for fleas and ticks

Question 15

Laner (isoxazoline) examples

Answer 15

1. Oral tablets
   -Bravecto, NexGard, Simparica, Credelio
   -ticks and fleas
2. Topical solution
   -bravecto, revolution plus, nexgard combo
   -remember to watch for transfer to owners

Question 16

Laner neurological adverse events

Answer 16

Can cause seizures if dogs are prone
*because they cause hyperexcitability of cells