DERMATOLOGY - Ectoparasite control - SAs Flashcards
What are the 3 commonest orders of the class Insecta to cause disease in small animals?
- Diptera (flies)
- Diphonaptera (fleas)
- Phthiraptera (fleas)
- use INSECTICIDES against these
What is the Order Acarina
- part of the class ‘ Arachnida’
- includes ticks and mites
- use ACARICIDES against these
What propotion of the flea population is present as an adult at a given point in time?
only 5% total population
What temperature and humidity are required for the flea LC?
Temp 20-30 degrees Relative Humidity (RH) of > 70%
What are the objectives of FAD therapy
- kill fleas in hair coat
- protect against re-infestation
- eliminate environmental reservoir and prevent future generations
What are the targets in flea control? 2
- ADULTS in hair (adulticide)
- IMMATURE STAGES in carpet/refuge (killed on emergence/not replaced due to adulticide, IGR or IDI, vacuum)
Name 5 traditional insecticides for fleas
- organophosphates
- organochlorides
- carbamates
- pyrethroids
- other botanicals
Name insecticides against fleas
- imidacloprid/ nitenpyram / dinotefuran
- fipronil/ pyriprole
- selamectin (stronghold)
- spinosad
- newer products
- (metaflumizone)
List some newer insecticides against fleas
- indoxacarb
- indoxacarb / permethrin
- fipronil / methoprene / amitraz
- spinosad
- fluralaner
- afoxolaner
What would an ideal flea tx do?
- kill flea before feeding (none do this)
- kill flea before it lays eggs (36h, existing products do this for 3 weeks)
Outline Spinosad (Comfortis) as a flea treatment
= adulticide
- tetracyclic macrolide
- targets nACH-R
- DOG and CAT
- fleas only
- rapid kill (80-100% at 4 hours)
- persists 3-4 weeks
- ORAL administration
- vomiting (5% dogs, up to 15% cats)
- DON’T GIVE WITH IVERMECTIN*
What is Certifect?
= Fipronil/ methoprene/ amitraz flea tx
- DOG ONLY
- spot on, every 4 weeks
- for fleas, Trichodectes canis (lice) and ticks (but doesn’t stop attachment)
What is Frontline combo?
= fipronil + methoprene (IGR)
- dog and cat
- extended ovicidal activity
- resistance?
- POM-V
What is Activyl/ Indoxacarb?
= new adulticide against fleas
- Na channel blocker
- bio-activation
- spot on every 4 weeks
- > 90% activity within 8 hours
- fleas only
What is Pyriprole?
= adulticide for fleas
- dog only
- fleas and ticks
What is Activyl Tick Plus (Indoxacarb + Permethrin)?
- flea adulticide
- DOG ONLY
- bioactivation
- spot-on, every 4 weeks
- AGAINST: fleas, ticks, Ixodes, Rhipicephalus, Dermacentor and Amblyomma
What is ‘Scalibor’?
- a 4% deltamethrin-impregnated collar
- 6 month activity (dog only)
- sandflies, mosquitos, ticks
- > 99% flea, >94% tick control for 6 months
- safe to combine with Activyl (Indoxacarb = flea adulticide)
What are the 2 main mechanisms of insecticide resistance?
- DETOXIFICATION - by hydrolases and mixed function oxidases
- TARGET SITE MODIFICATION - AChE, nAChE-R, Na-channel and GABA-R
What are the main concerns of resistance in agriculture??
- fipronil resistance
- imidacloprid resistance
Name 4 different IGR/IDIs
- LUFENURON - orally (dogs), injection/oral (cats)
- CYROMAZINE - household spray
- PYRIPROXIFEN - on animal, household spray
- METHOPRENE - on animal, household spray
What are the 2 different types of IGR?
- JUVENILE HORMONE ANALOGUES (JHA)
- INSECT DEVELOPMENT INHIBITORS (IDI)
How do juvenile hormone analogues work and give 2 examples
- disrupt growth in immature insects
- methoprene and pyriproxyfen
How do IDIs work and give an example
- inhibit chitin syntehsis
- lufenuron
Describe nitenpyram (capstar)
- oral
- flea only
- dog, cat
- no persistence
Describe spinosad (Comfortis)
- oral
- flea only
- dog, cat
- rapid kill, 3-4 weeks persistence
Describe Afoxolaner (NexGard)
- oral
- flea (5 weeks) and tick (4 weeks)
- dog only
Describe Fluralaner (Bravecto)
- oral
- flea (12 weeks) and tick (8-12 weeks)
- dog only
Describe the Fipronil spray
- dog, cat
- 4 week activity
- label (8,12 weeks)
- lice and ticks
Outline Indoxacard spot-on (Activyl)
- flea only
- dog and cat
Outline Imidacloprid (Advantage) spot-on
- flea only
- dog, cat and RABBIT
- efficacy reduced by wetting
Describe fipronil spot on treatment
- dog and cat
- flea and tick and lice
- > 4 week activity
Outline Pyriprole (Pract-tic) treatment
- dog only
- ticks
Describe imidacloprid/permethrin (Advantix)
- spot on
- flea and tick
- dog only
- NOT CAT!
Describe Dinotefuran/ permethrin/ pyriproxyfen (Vectra 3D)
- spot on
- flea and tick
- dog only
- NOT CAT
Define endectocide
An antiparasitic drug that is active both against endoparasites and against ectoparasites.
Name 2 spot-on endectocides
- SELAMECTIN: dog, cat, systemic
- IMIDACLOPRID/ MOXIDECTIN (Advocate): dog, cat, systemic, topical
What are the 3 options for treating sarcoptes?
- SELAMECTIN (stronghold, revolution) - twice, every month
- IMIDACLOPRID/ MOXIDECTIN (Advocate): twice every month
- AMITRAZ (Aludex) washes: weekly for 2-6 treatments
Which acaricidal product should you use for demodicosis?
- IMIDACLOPRID/ MOXIDECTIN (Advocate) - every 7 days
- AMITRAZ (Aludex) washes - weekly for 8-16 treatments
- NON-LICENSED ORAL TREATMENTS - ivermectin (not collies), milbemycin
Which acaricidal products can you use for ticks?
- FIPRONIL (spray or spot-on) - cats, dogs
- IMIDACLOPRID/ PERMETHRIN (spot on), DOGS
- INDOXACARB / PERMETHRIN spot on, dogs only
- DINOTEFURAN/ PERMETHRIN spot on, dogs only
- FIPRONIL + AMITRAZ - dogs
- AMITRAZ or DELTAMETHRIN collars - dogs only
- AFOXALANER, FLURALANER - dogs only
What is a new tick product for cats?
Seresto collar
- imidacloprid and flumethrin
- fleas and ticks for 7-8 months
- dogs: fleas, biting lice and ticks for 7-8 months
- flea activity of 5 month if wetting
Name 3 zoonotic ectoparasites of small animals
- fleas
- sarcoptic mange
- cheyletiellosis
How do phenylypyrazole insecticides work? Examples?
- target the GABA-gated chlorid channel in insect CNS
- fipronil, pyriprole
- spot on or spay fipronil have generally excellent control of adult cat fleas and egg production in cats and dogs.
- pyriprole similar results in lab dogs
What does the combination of fipronil (a pheylypyrazole insecticide) with (S)-methoprene do?
(S)-methoprene is a synthetic juvenile insect hormone analgouse. it inhibits egg development and adult emergence. combination is likely to delay resistance development and overcomes the lack of immediate adulticide activity when IGRs are administered alone.
Give 3 exampes of neonicotinoid insecticides
- imidacloprid
- nitenpyram
- dinotefuran
How do neonicotinoid insecticides work?
target the insecticide nicotinic acetylycholine receptor
How does imidacloprid work?
- spot on rapidly kills adult fleas
- provides > 4 weeks control in both dogs and cats
- larvicidal activity in unwashed bedding of treated cats persisted for > 18 weeks
Does Dinotefuran or Imidacloprid have a more rapid speed of kill?
Dinotefuran
Describe Nitenpyram action
- a water-soluble neonicotinoid (targets insect nicotinic Ach-R)
- exceptionally high bioavailability when administed orally to dogs and cats
- rapidly removes fleas
- adulticidal for 48 hours
What is special about spinosad?
it cobines rapid flea killing with persistent (30 day) efficacy following a single oral dose in dogs
What type of drug is selamectin?
a semi-synthetic avermectin
- effectively controls fleas on dogs and cats and home
How does Metflumizone work? How long for?
- induces a relaxed paralysis in insects by binding voltage- sensitive Na channels.
- 6 week action (spot on) thus exceeds the month-long effectiveness of most other spot-on products with the exception of those containing fipronil
Tx - localised demodicosis in young dogs
- often resolves spontaneiously
- decision to treat depends on case (sometimes just treat with benzoyl peroxide shampoo or gel)
Tx - generalised demodicosis
- aggressive treatment
- affected areas should be clipped
- total body clip generally advisable
How long should Aludex/ Amitrax be used for?
dip at 7 day intervals and continue for 10 weeks until at least 2 successive sets of skin scrapings fail to reveal live mites or eggs
In Advocate (Imidacloprid + moxidectin) what carries the acaricidal effect?
Moxidectin component
What is Promeris Duo?
Metaflumizone + Amitraz (provides the acaricidal effect)
Why do some animals benefit from a prewash with shampoo prior to amitrx treatmetn?
to degrease and descale the skin (might influence the efficacy of spot-ons that rely on skin lipids for absorption and distribution
What should you do in cases of canine demodicosis where amitraz and the imidacloprid-moxidectin (Advocate) combination doesn’t work or is not tolerated?
give oral ivermectin, milbemycin oxime or moxidectin
Describe acaricidal therapy for otodectic mange in dogs and cats
- TOPICAL = Surolan or Canaural, all animals in the house, 2-3 weeks, lack a specific acaricidal component but oily base may suffocate the parasites
- Selamectin (Stronghold) and moxidectin (Advocate) are licensed for this treatment in dogs and cats as a spot on. Resolve any other ectopic infestation too. Costly for many animals
- Ceruminolytics (cases with ear discharge)
- Home cleaning + appropriate environmental agent (Nuvan Staykill, Indorex or Acclaim)
How effective are acaricidal products in treating harvest mite infestation?
- very limited data
What can be used for treating harvest mite infestation?
DOGS:
- fipronil spray, once monthly, feet and ventrally
- permethrin / pyriproxyfen spot on or spray
CATS:
- selamectin monthly
- fipronil spray possible but may give shorter protection
BOTH:
- limit exposure to infested areas in late summer/ autumn if possible
What tick stage(s) can bite dogs?
nymph or adult stage
Where is tick treatment most important?
areas at ID risk of vector borne diseases:
- Babesia (Dermacentor, Rhipicephalus)
- Ehrlichia or Hepatozoon (Rhipicephalus)
- Anaplasma or Borrelia (Ixodes)
When is the period of prevention for tick infestation for the different species?
- Ixodes (spring and autumn)
- Rhipicephalus (end of spring to mid autumn)
- Dermacentor (autumn to spring)
How often are tick treatments repeated, generally-speaking?
Spot on: every 3 (4) weeks
Collars: every 4-7 months
Under optimal conditions
Outline the use of ivermectin as an ectoparasiticide
- not licensed in dogs or cats
- toxic to Collies and their crosses
- don’t use in puppies < 3 months old or kittens
- toxicity possible in any dog (warn owners)
- licensed products should always be used unless inappropriate
- very few circumstances where its use is justified in dogs although licensed products are now available for RABBITS and SMALL MAMMALS.
What drugs can you use in dogs against ticks?
- apply at least 2 days before arriving to a high-tick area
- Fipronil-(S)-methoprene spot on
- Pyriprole spot on
- Fipronil-methoprene-amitraz
- Imidacloprid-flumethrin collar
- afoxalaner
- fluralaner
What drugs can you use in cats against ticks?
- heavy tick infestations uncommon
- cats cannot be treated with amitraz or permethrin (arguably the most effective agents)
- Fipronil spot-on
- Fipronil-(S)-methoprene spot-on
- Imidacloprid-flumethrin collar
