L6: Louse infestations Flashcards
what are Phthiraptera
lice
pediculosis
infestation w/ lice
physical characteristics of lice (Phthiraptera)
wingless, dorsoventrally flattened insects
1-8mm long
lice eggs are called
nits
they attach to hairs or feathers on host
what type of lifecycle do fleas undergo
hemimetabolous (simple) metamorphosis
how many nymphal instars do lice have
3
nymphs resemble adults in appearance and behaviors
main way lice are transmitted
direct contact
most lice only survive a few days off of the host
how long does one lice generation take to complete
3-4 weeks
2 main groups of lice
Anoplura - sucking lice
Mallophaga - chewing (biting) lice
type of lice that only infest mammals, they feed on blood, and are slow moving
Anoplurs - suckling lice
type of lice that infests both birds and mammals, they move rapidly and feed on feathers, epidermal scales, sebum (some species feed on blood)
Mallophaga - chewing (biting) lice
how to tell Anoplura apart from Mallophage physically
Anoplura - head is narrower than prothorax and they have protrusible piercing mouthparts
Mallophage - head is broader than the prothorax and they have mandibulate mouthparts
Pediculosis infestations are more prevalent in animals in what conditions
- young
- old
- malnourished
- sick
- hosts living in unsanitary or crowded conditions
Mild to moderate pediculosis can cause what clinical symptoms
- pruritis and dermatitis (itchy, scratchy, biting of infected area)
- poor hair, feathers, and body condition
- restlessness and disruption of feeding, sleeping, etc
severe pediculosis infections are associated with what symptoms
- alopecia, production losses, secondary bacterial infections, anemia (suckling lice), death
T/F: Some lice species are able to transmit pathogens or parasitic worms
T
severe pediculosis may be a sign of an underlying condition such as..
malnutrition or chronic disease
how is pedculosis diagnosed
through clinical signs and detection of lice and or eggs
- biting lice move slower than suckling
- Taxonomic ID: transfer louse into saline, glycerin or mineral oil on a microscope slide
Treatment of Louse Infestations
- insecticides (carbaryl, coumaphos, pyrethoids)
- antiparasitic drugs (ivermectin, selamectin)
Prevention and Control of Louse Infestations
- disinfect the environment and fomites
- precent clean or recently treated animals from exposure to infested animals, fomites and environments
are there any known pathogens known to be transmitted by chicken lice
no
what are Menacanthus stramineus
chicken body louse
where are Menacanthus stramineus found on the body, where do they eggs cluster
chicken louse
on the skin, especially at the vent, breast and thigh regions where the bird is sparsely feathered so they can feed on blood
eggs cluster at the base of feathers, esp around the vent
what are Menopon gallinae
gallinae = chickens
chicken shaft louse
they rest on feather shafts
where can eggs of Menopon gallinae be found
attached either individually or in clusters to the base of feathers in the breast and thigh region
heavy lice infestations of dogs can cause what clinical signs
- severe pruritus
- restlessness
- intense scratching
- ruffled or rough matted coat
- alopecia
what is Linognathus setosus
dog suckling louse
think setosus - suckling
what is Trichodectes canis
dog chewing louse
intermediate host of tapeworm Dipylidium caninum
what is Felicola subrostraus
cat chewing louse
Linognathus vituli
longnosed cattle louse
what are Haematopinus eurysternus
shortnosed cattle louse
predilection for head (esp. around horns, eyes, ears), neck, dewlap and base of tail
what are Solenopotes capillatus
- little blue cattle louse
- smallest of the suckling lice that infest cattle
- usually found on head, neck, shoulders, dewlap, back, tail
- tend to occur in distinct clusters
what are Haematopinus quadripertusus
cattle tail louse
physical characteristic of Damalinia bovis that helps make them identifiable
dark transverse bands on their abdomen
louse of sheep that causes “louse worry” since it can reduce the quality and quantity of wool produced
Damalinia ovis
sheep chewing/body lice
what is Linognathus ovillus
sheep face louse
at high densities they will spread to other parts of the body
what is Linognathus pedalis and where are their predilection sites
sheep foot louse
predilection for feet, legs, belly (areas absent of wool)
what are Linognathus africanus
african blue louse (sucking lice of sheep and goats)
what is Linognathus stenopsis
goat sucking louse
* found over entire body
* primarily in short haired goat breeds
how are lice of equids transmitted
via direct contact and contaminated grooming equiptment, balnkets and tack
Damalina spp are _____ of goats
what is the important species to know>
chewing/biting lice
(mallophaga)
*Damalina caprae = goat biting louse
Damalinia equi
* horse chewing louse
* prefers neck, flanks, tail base
* numbers are greatest when winter coat is most dense
longer haired equine breeds are more prone to infestation by _______ equi
Damalinia horse chewing louse
what is Haematopinus asini
- horse suckling louse
- heavy infestations can cause anemia, loss of appetite, weight and vitality
predilection sites of Haematopinus asini
sites w/ coarse hair: forelock, mane, tail base, fetlock area
what is the one species of swine lice
Haematopinus suis = hog louse
- found worldwide, anywhere swine are raised
- prefer areas of thin skin (neck, jowl, flank, inner legs, inside ears)
