Flashcards in LEC 24 - Ectoparasiticides Deck (75):
What does the lifecycle of live consist of?
Entire thing takes place on the host animal. Will live on the host all year.
What are the two varieties of lice?
Chewing lice(Mallophaga) and Sucking lice(Anoplura)
What fleas attack dogs and cats?
How long do Ctenophalides live?
What are the major characteristics of the flea pupa?
Stable for about a year in the environment. Will hatch in response to vibrations.
What are the diseases that Ctenocephalides act as a vector for?
D. Caninum, D reconditum, and Bartonella henselae
What are the two types of ticks?
Hard ticks and soft ticks
What are some of the pathologies that ticks cause? (6)
Anemia, secondary infection. pruritus, paralysis, toxicosis, and disease transmission
What are the zoonotic external parasites?
Psoropte, D. immitis, and Cheyletiella (walking dnadruff)
What external parasites are reportable?
Psoroptes and Boophilus annulatus
What makes a ectoparasiticide a successful one?
Effect adulticide and repellatant. Persistant effect doses on skin for period of time. Stable in sunlight, shampoo, and water. Want minimal effects on the environment.
What are the ways that topical agents can pass trans-epidermally?
Intracellular diffusion and Transcellular
Where do drugs that pass trans-epidemally get confined to?
What factor affects absorption of a trans-epidermal drug?
thickness of the skin
What is the progression of animals from thin to thickest skin?
Pigs > Cattle > Dogs > cats
What is the process by which something is trans-follicularly absorbed?
Trans-epidermal and sweat pore
What is the mechanism by which something is absorbed into the sweat pores?
Accumulation in sebaceous glands and variation in this route due to hair structure of different species
How does fipronil work?
Non-competitive inhibitor of Glutamate-activated chloride channel. Causing rigid paralysis and CNS disruption
What is fipronil used for?
Fleas, ticks, and lice (topically). Trombicula autumnalis (Spray)
What are the adverse effects of fipronil?
5x's the maximum dose
How do the neonicotinamides work?
Agonist of insect postsynaptic, nicotinic AChR
What type of response does Imidaclorid cause?
Induces a biphasic response. Does so by increased spontaneous firing followed by nerve desensitization. Leading to death.
What are neonicotinamides used for?
Fleas, especially if they are resistant to fipronil.
What stages does imidaclopramide kill?
Adults and larvae; kill within 1 hour
What stages does nitenpyram kill?
Adults only; kills within 30 minutes
How are neonicotinamides adminstered?
What is the BA of neonicotinamides?
What are the adverse effects of imidacloprid?
Nicotinic and hepatic effects if ingested
What are the adverse effects of Nitenpyram?
No effects when administered to dogs or cats at 4x's the recommended dose.
How do pyrethrins work?
Activate Na+ channels in nerves, causing repetitive depolarizations leading to parasite death. 100 to 1000x's more selective for parasite then human.
Has you go up in pyrethrin generations how do the drugs change?
More stable and potent
What are the 1st generation pyrethrins?
What are the 2nd generation pyrethrins?
Phenothrin and resmethrin
What are the 3rd generation pyrethrins?
Permethrin and fenvalerate
What are the 4th generation pyrethrins?
Cyfluthrin and Cypermethrin
What are pyrethrins used for?
Fleas and ticks. 3rd generation chemicals cover some mites and lice.
Which of the pyrethrins can you NOT use on cats?
2nd generation or greater. Ingest by grooming and their metabolism requires glucuronidation.
What are the signs of pyrethrin toxicity?
SLUDGE. Salivation, Lacrimation, Urination, Defecation, GI distress, and Emesis. Also causes miosis, tremors, and dyspnea.
What are the synergist drugs?
Puperonyl butoxide and MGK264
How do the synergist drugs work?
Block cytochrome P450 in insects. Inhibits oxidative and hydrolytic metabolism. Prevents enzymatic breakdown of pyrethrins.
What are the adverse effects of MGK264?
What are the adverse effects of piperonyl butoxide?
Prevents breakdown of pyrethrins in cats, thereby increasing its toxicity.
What are the organophates used for? (ie. what methods of transmission, four of them)
Spray ons, ear tags, collars, and dips
What are the carbamates used for? (what methods of transmission, two of them)
Shampoos and collars
What organophosphates are used in spray-ons?
Fenthion and famphur
What organophostphates are used in ear tags?
Diazione and pirimphos
What organophosphates are used in collars?
Tetrachlorvinophos, diazinone, and dichlorvos
What organophosphates are used in dips?
Chlorpyriphos and phosmets
What Carbamates are used in shampoos?
What carbamates are used in collars?
How do carbamates and organophosphates work?
What neurons are affected when ACh-esterase is inhibited?
All presynaptic neurons in both the ANS and SNS. Postsynaptic muscle receptors and the postsynaptic PNS neurons.
What are the signs of organophosphate toxicity?
How do you treat ogranophosphate toxicity or carbamate toxicity?
What are the breeds of cattle that are sensitive to organophosphate toxicity?
Brahman, Charolais, and Simmental
What breeds of dogs are most sensitive to organophosphate toxicity?
Greyhounds and whippets
What is amitraz used for?
Demodex, fleas, ticks in dogs. Demodicosis in cats. Ticks, mites, and lice on swine and cattle.
What do you have to be careful with when it comes to using Taktic?
Can kill dogs and horses.
How does amitraz work?
MAO inhibitor in mites causing CNS toxicity.
What animal are most sensitive to amitraz sensitivity?
Toy breeds, dogs
What is the most common cause of toxicity with amitraz?
What receptor does amitraz react with in animals that causes a lot of secondary effects?
alpha-2 adrenergic effects
What are the symptoms of amitraz's reaction with alpha-r?
Sedation, bradycardia, vomiting, diarrhea, and ataxia. Transient hyperglycemia.
What is the reversal DOC for amitraz?
What are the two types of insect growth regulators?
Juvenile hormone analogs or Insect development inhibitors
How do the juvenile hormone analogs work?
Hormones that signal for maturation when they decrease, this will maintain them at high levels to prevent them from maturing
How do insect development inhibitors work?
Interfere with development of chitin exoskeleton. Drugs are consumed by fleas and excreted not absorbed. Flea larvae then feed off this feces.
How is lufenuron adminstered?
PO (dogs) and SC (cats)
How does lufenuron distribute in the body?
Accumulates in the adipose tissue and then redistributes to the plasma.
What are possible side effects to luferon?
Injection site reaction
How do repellants work?
Reduce insects landing on/entering the hair coat of animals. interfere with ectoparasite feeding. Ectoparastite disorientation.
What are the adverse effects of repellants?
DEET mar increase dermal absorption and increase adverse effects of primary ectoparasiticides in cats.
What are the three types of repellants?
Butoxypolypropylene, di-n-propyl isocinchomeronate, and diethyl-m-toluamide
What are the two types of juvenile hormone analogs?
Methoprene and pyriproxyfen