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| | '''[[Hypoderma spp.|''Hypoderma spp.'']] | | '''[[Hypoderma spp.|''Hypoderma spp.'']] |
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| | + | '''[[Oestrus ovis|''Oestrus ovis'']] |
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| | </big> | | </big> |
| − | ===''Oestrus ovis''===
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| − | *Also known as the sheep nasal bot fly
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| − | *Larvae parasitise the nasal chambers of sheep and goats
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| − | *Found in most sheep rearing areas of the world
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| − | '''Recognition'''
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| − | *13-15mm long
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| − | *Grey colouring
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| − | *Black spots on abdomen
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| − | *Clear wings
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| − | *Larvae have distinct black bands on each body segment
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| − | '''Life cycle'''
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| − | *Larvae are squirted into the nostrils of sheep in a jet of liquid by the adult fly
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| − | *The larvae crawl caudally into the nasal cavity and feed on the nasal mucosa and mature before returning to the nostrils
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| − |
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| − | *Larval development takes up to 2 months
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| − | **Larvae can overwinter in the nasal cavity if deposited late in the summer
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| − | *Once the larvae have developed they are sneezed out and pupate on the ground
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| − | *The adult fly emerges 1 months later
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| − | *Adult flies only live for 2-3 weeks
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| − | '''Pathogenesis'''
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| − | *Adult flies cause annoyance
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| − | **Interrupts feeding
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| − | **Leads to a decreased weight gain
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| − | *Larvae cause nasal irritation, nasal discharge and sneezing
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| − | **Irritate the nasal mucosa with oral hooks and spines causing a viscous exudate to be produced from which they feed
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| − | **Heavy infestations lead to erosion of the bones in the sinuses (turbinate bones)
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| − | **Penetration of the brain leads to '''false gid''' (high stepping gait and incoordination)
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| − | *[[Respiratory Parasitic Infections - Pathology#Oestrus ovis|Pathology in the nasal cavity]]
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| − | '''Control'''
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| − | *Systemic [[Ectoparasiticides|insecticides]] can be used in heavy infestations
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| − | *In warmer countries, strategic prophylactic treatment can be used
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| | ===''Gasterophilus spp.''=== | | ===''Gasterophilus spp.''=== |