Parasiticides and Insect Growth Regulators Flashcards
(50 cards)
1
Q
What are the three parts to ectoparasite control?
A
- On the pet: kill the adult insects –> parasiticides
- essential for flea insect allergic animals
- On the pet: prevent progression thru the life cycle –> insect growth regulators
- should be incorporated into all flea control programs
- In the environment: control for adults and other life stages
2
Q
What are the targets of parasiticides?
A
- Axon –> voltage gated Na channels; GABA-glutamate or Cl channels
- Synapse –> Ca, acetylcholine, acetylcholinesterase
3
Q
What 4 groups of parasiticides target axons?
A
- Incr Na flux: pyrethrins/pyrethroids
- Decr Na flux: metaflumizone, indoxacarb
- Incr GABA gated glutamate channels: macrocyclic lactones
- Decr GABA gated Cl channels: fipronil
4
Q
What 4 groups of parasiticides target the synapses?
A
- Choliesterase inhibitors: organophophates, carbamates
- Activation of nAch receptor gated Ca channels: spinosad, spinoteram
- Binding to nicotinic acetylcholine receptor: imidacloprid, nitenpyran, dinotefuran
- Monamine oxidase inhibitors: amitraz
5
Q
Describe pyrethrins
A
-
incr Na permeability along axons
- leads to hyperexcitation and death
- derived from chrysanthemum
- good:
- safe - okay for cats and puppies
- quick flea knock down
- bad:
- UV inactivated
- short duration of action
6
Q
Describe pyrethroids
A
- Good:
- binds to hair, skin
- more photo-stable
- longer duration of action
- repels and kills fleas, ticks, mosquitoes if >2%
- Bad:
- incr toxicity
-
never apply directly to a cat!
- >0.5% = toxic to cats
- washed off by bathing
7
Q
What are examples of pyrethroid/permethrin veterinary products?
A
- Advantix II - 55% permethrin
- Actvivyl plus
- Vectra 3D - 33% permethrin,
8
Q
Describe deltamethrin
A
- pyrethroid ester insecticide
- kills flea and ticks
- repels mosquitoes, Culicoides
- available as collar
- last 6 mo
- water resistant
- can cause local irritation
9
Q
Describe indoxacarb
A
- blocks voltage dependent Na channels, interrupting the nerve impulse
- results in reduced feeding, paralysis and death of flea
- uses metabolic bioactivation in the flea to kill
- safe for mammals
- water safe, topical once a month
- canine product also has permethrin
10
Q
Describe fipronil
A
- inhibits GABA gated Cl channels –> axonal hyperexcitation
- flea adulticide
- also used in agriculture
11
Q
Describe Frontline Plus (fipronil + methoprene)
A
- Good:
- concentrates in sebaceous glands
- photo-stable
- safe for puppies and kittens
- water immersion - no change in efficacy
- combines IGR + adulticides
- activity on both fleas and ticks; safe in cats
- Bad:
- does not repel
- bathing w/ medicated shampoo appears to decr efficacy clinically
- reported decr efficacy in field
12
Q
What is Tritak?
A
- For dogs: fipronil and cyphenothrin and methoprene
- for dogs only
- For cats: fipronil, etofenprox, methoprene
13
Q
Describe Bravecto
A
- oral flea and tick control (also a topical)
- up to 12 wks of protection against fleas and ticks
- selective inhibition of arthropod GABA and l-glutamate-gated Cl channels
- for dogs > 6 mo
- effective for demodex
14
Q
Describe Nexgard (Afoxolaner)
A
- oral flea and tick control for 30d
- 100% kill within 24h
- for dogs only
- non-competitive GABA receptor antagonist, much more selective for GABA receptors in insects or ticks, than for those in mammals
15
Q
Describe Simparica (Sarolaner)
A
- oral, chewable, for dogs
- kills ticks and fleas for up to 35 d
- effective against demodex
- more effective toward the end of the month compared to Nexgard
16
Q
What parasiticides target the synapse?
A
- organophosphates
- carbamates
- spinosad
- imidacloprid
- nitenpyram
- dinotefuran
17
Q
Describe organophosphates
A
- no longer recommended!
- cholinesterase inhibitors
- used by licensed pesticide operators for mosquito and agricultural pest control
-
toxic to cats and young animals
- muscular twitching –> seizures
- antidotes: atropine and antihistamines
18
Q
Describe carbamates
A
- no longer recommended!
- less toxic, less effective
- competes irreversibly w/ cholinesterase
- toxic signs: same as OPs
- antidote: atropine
- used less frequently, environmental products only available
19
Q
Describe Spinosad
A
- Non-antibiotic tetracycline macrolide
- Activates nicotinic acetycholine receptors –> hyperexcitation –> death
- Comfortis, Trifexis
- Oral, once monthly
- Works systemically
- Should be given w/ food
- Should not be given to dogs receiving high doses of ivermectin
- Lowers threshold for seizures
20
Q
Describe Comfortis
A
- Spinosad
- approved for dogs and cats
- Good:
- chewable 1x/month tablet, no effect of bathing
- flavored with beef and pork
- starts killing fleas within 30 minutes, 100% effective within 4 hours
- flea adulticide effects last for 30d
- Bad:
- does not repel fleas
- vomiting is freq after administration
- no IGR
21
Q
Describe Spinoteram (Cheristin)
A
- alters function of nicotinic and GABA channels
- does not interfere with other GABA binding products
- topical
- once a month
- very fast killing (<12 hrs)
22
Q
Describe Imidacloprid
A
- Chloronicotinyl nitroguanidine insecticide
- Binds and stimulates insect nicotinic acetylcholine receptor
- Advantage
- Good:
- Once a month spot on for dogs and cats
- Flea adulticide, effective
- Safe, non-teratogenic, non-mutagenic
- Bad:
- removed by water immersion/bathing
- does not repel fleas; no effect on ticks
- No IGR
23
Q
What are examples of imidacloprid products?
A
- Advantage II
- Advantix II
- Advantage Multi - Rx
- Seresto (collar)
24
Q
Describe Advantix II
A
- imidacloprid, permethrin (44%), pyripoxyfen
- kills 98-100% fleas within 12 hrs
- repels fleas, ticks and mosquitoes
- somewhat water proof
- for dogs only!
25
Describe Seresto
* flumethrin and imidacloprid
* _safe for cats_
* no need to remove for bathing
* lasts 8 mo
* repels ticks
* **kills but does not repel fleas**
26
Describe Nitenpyram
* binds and inhibits nicotinic acetylcholine receptors
* Capstar (Novartis)
* given PO - dog and cat as often as q 24hrs
* not flavored: used in animals undergoing food trial
* useful in clinics, boarding facilities, dogs, going to public places, severe infestations
27
What the benefits and hindrances of Capstar?
* Good:
* kills 90% of fleas in dogs in 4hrs and cats within 6 hrs
* 100% effective for 24 hrs
* safe in pups and kittens
* okay to use with other products
* Bad
* only lasts 24 hrs
* does not repel
* no IGR
28
Describe Dinotefuran
* novel 3rd generation neonicotinoid
* flea adulticide, quick kill
* binds permanently to insect acetylcholine receptors --\> hyperexcitation --\> death
* binds to a different site of the nAch receptor where imidacloprid binds
* does not bind to mammalian acetylcholine receptors
29
Describe Vectra 3D
* dinotefuran, pyriproxifen, permethrin
* Good:
* has an IGR, adulticide and repellent in 1 product
* labeled for fleas (all stages) ticks and mosquitos
* Bad:
* efficacy decr by bathing
* limited freq of application to q 4 wks
* permethrin - toxic to cats
30
What are 3 examples of insect growth regulators?
1. methoprene
2. pyriproxifen
3. lufenuron
31
Describe Methoprene
* molt from 3rd stage larvae --\> pupae requires a decr in "insect juveile hormone #1"
* methoprene mimics JH-1 --\> **prevents molting**
* products = Precor, Frontline Plus
* Good:
* active against several insects, including fleas
* available for on pet and environmental use
* Bad:
* photo-inactivated
* no adulticide
* does not repel
32
Describe Pyriproxifen
* Products: Nylar, Vectra 3D
* Good:
* works for up to 6 mo
* effects eggs and larva
* may also have delayed flea adulticide activity
* it is available over the counter for use in the environment
* stable for use in both indoor/outdoor environment for many months
33
Describe Lufenuron
* chitin synthesis inhibitor
* used in combo products
* must be given with food
* cats need higher dose than dogs
* prevents flea repro after a blood meal
* Good:
* oral, q 1 mo
* very safe for dogs and cats
* Bad:
* no adulticide
* does not repel
* lab phase: 3 mo if this product is used alone for flea control
34
Describe macrocyclic lactones
* potentiate GABA and glutamate gated chloride channels to interrupt axonal nerve transmission
* Milbemycin (Sentinel, Novartis)
* Once a month, chewable tablet- pork flavored
* For dogs, cats: 4 wks or older
* Labeled for:
* Hw
* Hookworms
* Roundworms
* Whipworms
35
Describe ivermectin
* Heartgard Plus: ivermectin + pyrantel
* once a month chewable tablets - beef flavored
* D. immitis, hookworms, roundworms
* off lable uses: demodex and sarcoptes
* no efficacy against fleas or ticks
36
Describe Selamectin
* Revolution
* Top spot, systemically absorbed, 1x/ month
* Good:
* _Systemic absorption_ should minimize impact of bathing
* Broad label claims
* K9: ear mites, Sarcoptes, HW, dermacentor
* in cats: hookworms, roundworms
* Bad:
* poor efficacy against fleas
* breakthroughs reported for HW prevention
* does not repel as it works after systemic absorption
* no IGR
37
Describe Moxidectin
* macrocyclic lactone
* products: Advantage Multi
* topical product for cats and dogs
* 1x/month
* good: flea and heartwrom control in 1
* bad:
* decr efficacy of imidacloprid w/ bathing
* ivermectin sensitive breeds - ingestion, OD
38
Describe formanidines
* Products: Amitraz, Mitaban (topical for demodicosis)
* Monoamine oxidase inhibitor
* inhibits degradation of NT in synapse
* **toxic in horses and cats**
39
What is Certifect?
* Amitraz and fipronil
* for dogs only!
* repellent and adulticide
* fleas and ticks
* topical
* once monthly
* works by contact
* reported cases of PF
40
What parasiticide increases Na flux?
permethrin
41
What parasiticide decreases Na flux?
metaflumizone
42
What parasiticide increases GABA gated glutamate channels?
selamectin
43
Which parasiticide decreases GABA gated Cl channels?
Fipronil
44
What parasiticides cholinesterase inhibitors?
* OPs
* carbamates
45
What parasiticide decreases neurotransmitter degradation (MO inhibitor)?
Amitraz
46
Which parasiticides mimic Ach?
* Imidacloprid
* Nitenpyram
* Dinotefuran
47
Describe non-chemical environmental flea control
* Diatomaceous earth - indoor/outdoor
* naturally occurring
* absorbs lipids from the waxy outer layer of insects' exoskeletons--\> dehydration
* _physical damage_ of exoskeleton
* Beneficial nematodes
* *Steinernema* and *Heterorhabditis*
* release toxic bacterium which kills the host larva within 24-48h, UV and draught harm nematodes
* Sodium polyborate - indoor only
* dessicant
* best if professionally applied
* will last 1 yr if carpet not shampooed
48
What are some chemical products that can be used for environmental flea control?
* Outdoor
* Yard tx (Virbac) - synthetic pyrethroid
* Indoor
* Low % permethrin and Nylar (knockout tx area)
49
What are the general rules for environmental flea control?
* should be focused on areas protected from UV light, moist
* repeat every 3 wks at peak of season
* combo of adulticide and IgR
50
What are cat-safe parasiticides?
* Advantage
* Frontline tritak for cats
* Fipronil
* Activyl
* Vectra for cats (2D)
* Revolution
