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Blowfly strike is a serious disease worldwide in sheep of all ages. It is caused by 'blowflies' laying eggs in damaged areas of skin. Larvae then hatch and eat the skin causing severe and debiliatating disease. The disease can also occur in rabbits and is incredibly distressing to rabbit owners.
Blowfly strike is a serious disease worldwide in sheep of all ages. It is caused by 'blowflies' laying eggs in damaged areas of skin. Larvae then hatch and eat the skin causing severe and debiliatating disease. The disease can also occur in rabbits and is incredibly distressing to rabbit owners.
Blowflies are divided into categories depending on their ability to initiate strike. Primary flies are capable of initiating a strike on living sheep and larvae can penetrate intact ski. These are ''Lucilia, ''''Phormia and ''''Calliphora spp. ''Secondary flies cannot initiate a strike. Larvae attack an area already struck or damaged, extending it. ''Ca''''lli''''phora spp. and ''''Chrysomya spp.'''''<b>(in warmer climates)are examples of these. Tertiary flies attack lesions on carcasses which have become dry; ''Musca and '''</b>''Sarcophaga spp. ''cause this.
Blowflies are divided into categories depending on their ability to initiate strike. Primary flies are capable of initiating a strike on living sheep and larvae can penetrate intact ski. These are ''Lucilia, '''Phormia and ''Calliphora spp'''''. '''Secondary flies cannot initiate a strike. Larvae attack an area already struck or damaged, extending it. ''Calliphoria'' and ''Chrysomya spp''.(in warmer climates) are examples of these. Tertiary flies attack lesions on carcasses which have become dry; ''Musca'' and ''Sarcophaga spp. ''cause this.
Predisposing factors to flystrike include:<br>
Predisposing factors to flystrike include:<br>
== <br> Clinical signs ==
== <br> Clinical signs ==
Animals are first, usually seen standing away from the flock. Anorexia, depression and listlessness will then be noted. The fleece may appear darker, be damp and have a foul smell. At closer inspection the skin will appear sore and presence of maggots may be seen.
Animals are first, usually seen standing away from the flock. Anorexia, depression and listlessness will then be noted. The fleece may appear darker, be damp and have a foul smell. At closer inspection the skin will appear sore and presence of maggots may be seen.
== <br> Treatment and Control ==
== <br> Treatment and Control ==
Human slaughter may often be the only treatment in severe cases. Scraping the affected tissue and removing the mites has also been performed. The sheep will need to be isolated and kept inside in a dry area so as to prevent more infection.
Human slaughter may often be the only treatment in severe cases. Scraping the affected tissue and removing the mites has also been performed. The sheep will need to be isolated and kept inside in a dry area so as to prevent more infection.
Control measures are so much more effective than treatment. These include:
Control measures are so much more effective than treatment. These include:
'''Prophylactic '''[[Ectoparasiticides|'''insecticide''']]'''treatment'''. This must kill larvae and remain in fleece to prevent flies from laying eggs. These can be applied by spraying, dipping, spray race or jetting.
'''Prophylactic '''[[Ectoparasiticides|'''insecticide''']]'''treatment'''. This must kill larvae and remain in fleece to prevent flies from laying eggs. These can be applied by spraying, dipping, spray race or jetting. '''Insect growth regulators''' in pour on form, such as cyramazine will provide 2-4 month protection depending upon the product used.
'''Insect growth regulators''' in pour on form, such as cyramazine will provide 2-4 month protection depending upon the product used.
'''Effective worm control''' is vital to minimise diarrhoea and therefore soiled fleeces. Crutching can also be performed especially in ewes to prevent soiling.
'''Effective worm control''' is vital to minimise diarrhoea and therefore soiled fleeces. Crutching can also be performed especially in ewes to prevent soiling.
'Mule's operation', which is the surgical removal of breech skin in Merino breeds will help prevent the disease in this breed.'''Tail docking of lambs''' is readily practiced in many countries and this also decreases the incidence of soiling of the fleece.
'Mule's operation', which is the surgical removal of breech skin in Merino breeds will help prevent the disease in this breed.'''Tail docking of lambs''' is readily practiced in many countries and this also decreases the incidence of soiling of the fleece.
Proper carcass disposal eliminates fly breeding sites on farms.
Proper carcass disposal eliminates fly breeding sites on farms.
Vaccination has been used against the gut lining of blowflies in Australia, but this has only in the research stages.
Vaccination has been used against the gut lining of blowflies in Australia, but this has only in the research stages.
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[[Category:To_Do_-_Review]]
[[Category:To_Do_-_Review]]