Ectoparasites 4 Flashcards
what is myiasis?
parasitic infection of the body of a live animal by fly larvae
what species cause wool strike in sheep?
Lucilia cuprina
Lucilia sericata
what are the predisposing factors of wool strike in sheep?
soiled wool
heavy rain
high humidity, high temperature
skin folds
what families take part in myiasis?
Calliphoridae
Sarcophagidae
what are the distribution patterns in wool strike in sheep?
perineum, genitalia: urine, feces, breeding, lambing
head: butting
feet: foot rot
flanks, ventral neck, withers: fleece rot after heavy rain
how do you treat wool strike?
clip soiled wool
wound management and removal of larvae
drug depending on species
preventative measures
what are some drug options for wool strike?
dips/plunges/sprays/jetting with organophosphates
insect growth regulators
SC avermectins: less effective
when is fly strike in rabbits with moist dermatitis most prevalent?
summer in temperate climate
what are some predisposing factors for fly strike in rabbits with moist dermatitis?
husbandry
outdoor or mixed outdoor/indoor
dental diseases
obesity
diarrhea
urinary tract diseases
how is fly strike in rabbits/dogs/cats treated?
clipping, mechanical removal of larvae
wound management
supportive care
topical antibiotics
systemic antibiotics
subcutaneous avermectins
Nitenpyram (capstar)
address underlying condition
are bots and grubs species-specific?
yes
what species are cattle grubs?
Hypoderma bovis
Hypoderma lineatum
what is the veterinary relevance in economic losses of cattle grubs?
decreased milk production
weight loss
depreciation value carcass
how are cattle grubs treated?
mechanical removal
drug
pour-on avermectins or organophosphates
what causes cuterebriasis?
Cuterebra spp
what are the hosts of Cuterebra spp?
obligate: rodents and lagomorphs
accidental: dogs, cats, humans
what are the mechanisms that Cuterebra spp use?
tissue damage and secondary infections
ectopic or aberrant larva migrans
anaphylactic reactions
what can larva migrans cause with Cuterebra spp?
ischemic encephalopathy in cats
neurologic abnormalities
ocular diseases
how are Cuterebra spp treated?
mechanical removal
what causes nematode dermatitis in bovine?
Stephanofilariasis
what is the vector of Stephanofilariasis?
Hematobia irritans: fly
what does Stephanofilariasis cause?
variable pruritus
papulocrustous dermatitis
what causes nematode dermatitis in dogs/bovine?
Pelodera strongyloides
how do dogs, cattle, swine, horses, rodents, humans get infected with Pelodera strongyloides?
L3 invade skin
direct contact
how is Pelodera strongyloides diagnosed?
skin scrapings or hair plucking
skin biopsy
what is the treatment for nematode dermatitis?
clean environment
avermectins
what families cause myiasis?
calliphoridae: blowflies
sarcophagidae: flesh flies
what parasites are in the calliphorida?
facultative: Lucilia cuprina
obligate: Cochliomyia hominivorax
how many eggs can an adult female calliphoridae fly lay?
200
what subfamilies are in the family oestridae?
oestrinae: sheep nasal bots
hypodermatinae: cattle grubs
cuterebrinae: rodent bot fly
what is the veterinary relevance of cattle grubs in the mechanisms by which they cause problems?
irritation, excitability of adult flies
tissue damage: larva migrans and cysts
ectopic or aberrant larva migrans: brain
anaphylactic reactions
what are the differentials for what stephanofilariasis causes?
pelodera
dermatophytosis
pyoderma
demodicosis
chorioptic mange
contact dermatitis
how do you treat stephanofilariasis?
topical organophosphates
ivermectin
how can parasites in myiasis be identified?
third-stage larvae
posterior spiracles
what is the life cycle for wool strike in sheep?
10-21 days
what preventative measures can be employed for wool strike?
tail amputation
clip lumbar/perigenital areas
Mules’ operation
what is the most prevalent cause of death in rabbits?
myiasis
toxemia, sepsis follow
who can you give nitenpyram (capstar) to?
dogs
cats
reptiles
who do cattle grubs infect?
cattle
european deer
occasionally horses
humans
alpacas
when should you use pour-on avermectins with bot flies?
after adult flies’ activity ceases to avoid neurological or gastrointestinal adverse effects due to larvicidal treatment
is stephanofilariasis seasonal?
no
what is the distribution and clinical signs of stephanofilariasis?
ventral distribution, face, neck
variable pruritis, papulocrustous dermatitis
what are the clinical signs of Pelodera strongyloides?
variable pruritic
erythema, alopecia, scaling, crusting, pustules
ventral distribution
how is Pelodera strongyloides treated?
avermectins
2 applications moxidectin/imidacloprid 2 weeks apart
clean environment
