|
|
| (43 intermediate revisions by 4 users not shown) |
| Line 1: |
Line 1: |
| − | {{unfinished}}
| + | #REDIRECT[[:Category:Lice]] |
| − | | |
| − | {{toplink
| |
| − | |backcolour =
| |
| − | |linkpage =Insecta
| |
| − | |linktext =INSECTA
| |
| − | |pagetype=Bugs
| |
| − | |sublink1=Parasites
| |
| − | |subtext1=PARASITES
| |
| − | }}
| |
| − | <br>
| |
| − | | |
| − | ==Phthiraptera Introduction==
| |
| − | [[Image:Arthropod classifiation.jpg|thumb|right|150px|Arthropod Classification - copyright nabrown RVC]] | |
| − | Lice are obligate ectoparasites of every avian and most mammalian species. They are only a few milimetres long and like [[Fleas - WikiBlood|fleas]], are wingless but unlike [[Fleas - WikiBlood|fleas]] are dorsoventally flattened.
| |
| − | | |
| − | Lice are host specific, permanent parasites which cause pediculosis. The louse saliva and faeces contains allergenic substances which causes irritation, rubbing, licking and skin damage to the host which will decrease the host's productivity.
| |
| − | | |
| − | Mammalian lice species have a single pair of claws on the ends of stout legs, whereas avian lice species have a double claw on each leg.
| |
| − | | |
| − | There are two main groups of veterinary importance, the mallophaga (chewing lice) and anoplura (sucking lice).
| |
| − | | |
| − | ==Mallophaga==
| |
| − | ''Also known as '''chewing lice''' or '''biting lice''' ''
| |
| − | | |
| − | *Broad head
| |
| − | | |
| − | *Thorax narrower than the head
| |
| − | | |
| − | *Rasping mouthparts
| |
| − | | |
| − | *Feeds on epithelial scales, scabs, feathers and other bodily debris
| |
| − | | |
| − | *Speices occurs on both mammals and birds
| |
| − | | |
| − | ==Anoplura==
| |
| − | [[Image:Sucking Louse.jpg|thumb|right|150px|Sucking Louse ''Pediculosis humanus'' - From: Genetic Analysis of Lice Supports Direct Contact between Modern and Archaic Humans Reed DL, Smith VS, Hammond SL, Rogers AR, Clayton DH PLoS Biology Vol. 2, No. 11, e340 doi:10.1371/journal.pbio.0020340]]
| |
| − | ''Also known as '''sucking lice''' ''
| |
| − | | |
| − | *Narrow head
| |
| − | | |
| − | *Thorax wider than the head
| |
| − | | |
| − | *Powerful legs
| |
| − | | |
| − | *Piercing mouthparts
| |
| − | | |
| − | *Feed on blood and tissue fluids
| |
| − | | |
| − | *Heavy infestations can cause anaemia
| |
| − | | |
| − | *Species occur only on mammals
| |
| − | | |
| − | ==Life Cycle==
| |
| − | | |
| − | *The whole life cycle takes 2-3 weeks
| |
| − | | |
| − | *The lice spends its whole life on the animal
| |
| − | **But, can survive for one week off the animal
| |
| − | | |
| − | *In some species parthenogenesis can occur
| |
| − | | |
| − | *Close contact transmission can occur
| |
| − | | |
| − | '''1. Eggs'''
| |
| − | | |
| − | *Known as nits
| |
| − | | |
| − | *Cemented to hairs
| |
| − | | |
| − | '''2. Nymphs'''
| |
| − | | |
| − | *Nymphs hatch from the egg (no larval stage)
| |
| − | | |
| − | *Undergoes several moults
| |
| − | | |
| − | '''3. Adults'''
| |
| − | | |
| − | *Females can lay up to 10 eggs per day
| |
| − | | |
| − | ==Pediculosis==
| |
| − | | |
| − | *Pediculosis is an infestation of lice
| |
| − | | |
| − | *Pediculosis in farm animals in most usually seen in winter when the coat is thickest
| |
| − | | |
| − | *Debilitated animals are often lousy as they cannot groom properly
| |
| − | | |
| − | ===Cattle===
| |
| − | | |
| − | *One chewing louse
| |
| − | **Bovicola bovis
| |
| − | | |
| − | *Several sucking lice
| |
| − | **E.g. Linognathus vituli
| |
| − | | |
| − | *Most lice have a preferred predilection site on the body
| |
| − | | |
| − | *Some lice will gather in clusters
| |
| − | | |
| − | *Causes ill-thrift, anaemia and can lead to down-graded leather
| |
| − | | |
| − | ===Sheep===
| |
| − | | |
| − | *One chewing louse
| |
| − | **Damalinia ovis
| |
| − | | |
| − | *Two sucking lice
| |
| − | **Lignognathus spp.
| |
| − | ***The 'foot louse' and the 'face louse'
| |
| − | | |
| − | *Causes fleece damage
| |
| − | | |
| − | ===Pigs===
| |
| − | | |
| − | *One sucking louse
| |
| − | **Haematopinus suis
| |
| − | **Large 5mm louse which is easily visible on the skin
| |
| − | **Vector of African swine fever virus and rickettsiae
| |
| − | | |
| − | ===Horses===
| |
| − | | |
| − | *One chewing louse
| |
| − | **Damalinia equi
| |
| − | | |
| − | *One sucking louse
| |
| − | **Haematopinus asini
| |
| − | | |
| − | *Mainly in the mane and tail but can spread over the body
| |
| − | | |
| − | ===Dogs===
| |
| − | | |
| − | *One chewing louse
| |
| − | **Trichodectes
| |
| − | | |
| − | *One sucking louse
| |
| − | **Linognathus setosus
| |
| − | | |
| − | *Neglect is usually associated with heavy infestations
| |
| − | | |
| − | ===Cats===
| |
| − | | |
| − | *One chewing louse
| |
| − | **Felicola
| |
| − | | |
| − | ===Poultry===
| |
| − | | |
| − | *Several species of chewing lice
| |
| − | **Lipeurus spp. are the most pathogenic
| |
| − | ***E.g. the 'wing louse' and the 'head louse'
| |
| − | **Menacanthis spp. are also pathogenic
| |
| − | ***Lays its eggs in clusters around the [[The Avian Vent and Cloaca - Anatomy & Physiology|cloaca]]
| |
| − | | |
| − | *No sucking lice
| |
| − | | |
| − | ==Control==
| |
| − | | |
| − | *Few insecticides will kill lice eggs on the animal
| |
| − | | |
| − | *Two treatments are needed to kill nymphs emerging from eggs at the time of the initial treatment and those that will emerge 2-3 weeks later
| |
| − | **At two week intervals
| |
| − | **Or a product with a two week residual activity can be used
| |
| − | | |
| − | Anopleura lice are more susceptible to systemic insecticide treatment than mallophaga lice
| |
| − | | |
| − | *Resistance to insecticides may become a problem so alternating the chemicals used and avoiding pour on treatments (which have a greater risk of resistance developing) should be considered
| |