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| | [[Coccidiosis - Poultry]] | | [[Coccidiosis - Poultry]] |
| − | '''Pathogenesis'''
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| − | *7 important ''Eimeria'' species
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| − | *4 malabsorptive species
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| − | **''Eimeria acervulina'' which is moderately pathogenic
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| − | **''Eimeria maxima'' which is moderately pathogenic
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| − | **''Eimeria mitis'' which has low pathogenicity
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| − | **''Eimeria praecox'' which has low pathogenicity
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| − | *3 haemorrhagic species
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| − | **''Eimeria tenella''
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| − | **''Eimeria necatrix''
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| − | **''Eimeria brunetti''
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| − | **All highly pathogenic
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| − | **Form large sub-epithelial second generation schizonts at the base of intestinal crypts
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| − | **Deep eruptions form when cells rupture to release merozoites
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| − | **Destruction of crypt stem cells and marked haemorrhage
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| − | **Blood stained faeces
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| − | **High morbidity and high mortality
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| − | '''Diagnosis'''
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| − | *Post-mortem diagnosis of lesion severity
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| − | **Region of intestine affected
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| − | **Appearance of lesion
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| − | **Presence or absence of haemorrhage
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| − | **Size of schizonts and oocysts found in mucosal scrapings
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| − | *''Eimeria acervulina''
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| − | **Proximal gut
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| − | **Thickening of walls
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| − | **'White ladder lesions' produced by dense foci of gamonts and oocysts
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| − | **Watery exudate
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| − | *''Eimeria maxima''
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| − | **Mid-gut
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| − | **Thickening of walls
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| − | **Pink exudate
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| − | *''Eimeria tenella''
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| − | **Swollen [[Caecum - Anatomy & Physiology|caeca]]
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| − | **Thickening of wall
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| − | **Dark colouring containing a core of necrotic tissue and blood
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| − | *Lesion scoring is the best method of diagnosing the severity of the lesions and therefore the causative ''Eimeria'' species
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| − | *''Eimeria necatrix''
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| − | **Mid-gut
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| − | **Ballooning of wall
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| − | **White spots and petechiae forming 'salt and pepper' lesions
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| − | **Haemorrhage into lumen
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| − | '''Immunity'''
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| − | *Different ''Eimeria'' species produce different levels of protective immunity
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| − | **''E.maxima'' -> ''E.brunetti'' and ''E.acervulina'' -> ''E.tenella'' and ''E.necatrix''
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| − | *There is no cross immunity between species
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| − | *There is very little passive immunity
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| − | *Evokes a cell-mediated response
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| − | *All ages of poultry are susceptible
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| − | '''Epidemiology'''
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| − | *Oocysts are ubiquitous and robust
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| − | **Able to survive several months to years
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| − | *It is impossible to keep buildings free from infection
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| − | **Chicks become infected by pecking the ground shortly after being placed in the poultry house
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| − | *Biotic potential is enormous
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| − | **Generation time is short
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| − | **Massive infections can build up rapidly
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| − | *Immunity develops relatively slowly
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| − | **With high stocking densities the situation is explosive
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| − | '''Control'''
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| − | *Chemical
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| − | **Intensive poultry production is largely dependent on the use of anticoccidial drugs
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| − | **For more information see [[Anti-Protozoal Drugs|here]]
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| − | *[[Vaccines - WikiBlood|Vaccines]]
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| − | **Paracox
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| − | ***Multivalent attenuated [[Vaccines - WikiBlood#What antigen(s) do we use in the vaccine?|live vaccine]] for replacement layers and broilers
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| − | ***Contains 7 live strains of ''Eimeria''
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| − | ***Lack the most pathogenic life cycle stage making the prepatent period shorter
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| − | ***Known as '''precocious''' strains
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| − | ***Chicks [[Vaccines - WikiBlood|vaccinated]] on a single occasion when 1-9 days old through oocyst suspension in the feed or water
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| − | ***[[Vaccines - WikiBlood|Vaccinated]] birds have sub-optimal growth rates so is not used for broilers
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| − | **Paracox 5
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| − | ***Contains 5 strains of the most pathogenic ''Eimeria''
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| − | ***Used for broilers
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| − | ***Sprayed onto the first feed offered to new batches of chicks
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| − | *Integrated control
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| − | **Careful management is needed so in-feed prophylaxis and [[Vaccines - WikiBlood|vaccination]] do not fail
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| − | **Remove litter and thoroughly clean houses in between crops
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| − | ***Optimum turn-around time is 10 days
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| − | **Use the lowest stocking density which is compatible with economic production
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| − | **Water bowls, roofs and walls should be well maintained to prevent litter becoming damp
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| − | **Stress factors should be avoided and adequate nutrition provided
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| | ==Other Avian Coccidia== | | ==Other Avian Coccidia== |