Difference between revisions of "Coccidiosis - Poultry"
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− | + | [[Coccidia - Poultry]] | |
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− | [[ | ||
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− | + | '''Pathogenesis''' | |
+ | *7 important ''[[Eimeria spp.|Eimeria]]'' species | ||
− | + | *4 malabsorptive species | |
+ | **''[[Eimeria spp.|Eimeria]] acervulina'' which is moderately pathogenic | ||
+ | **''[[Eimeria spp.|Eimeria]] maxima'' which is moderately pathogenic | ||
+ | **''[[Eimeria spp.|Eimeria]] mitis'' which has low pathogenicity | ||
+ | **''[[Eimeria spp.|Eimeria]] praecox'' which has low pathogenicity | ||
− | + | *3 haemorrhagic species | |
+ | **''[[Eimeria spp.|Eimeria]] tenella'' | ||
+ | **''[[Eimeria spp.|Eimeria]] necatrix'' | ||
+ | **''[[Eimeria spp.|Eimeria]] brunetti'' | ||
+ | **All highly pathogenic | ||
+ | **Form large sub-epithelial second generation schizonts at the base of intestinal crypts | ||
+ | **Deep eruptions form when cells rupture to release merozoites | ||
+ | **Destruction of crypt stem cells and marked haemorrhage | ||
+ | **Blood stained faeces | ||
+ | **High morbidity and high mortality | ||
− | + | '''Diagnosis''' | |
+ | *Post-mortem diagnosis of lesion severity | ||
+ | **Region of intestine affected | ||
+ | **Appearance of lesion | ||
+ | **Presence or absence of haemorrhage | ||
+ | **Size of schizonts and oocysts found in mucosal scrapings | ||
− | + | *''[[Eimeria spp.|Eimeria]] acervulina'' | |
+ | **Proximal gut | ||
+ | **Thickening of walls | ||
+ | **'White ladder lesions' produced by dense foci of gamonts and oocysts | ||
+ | **Watery exudate | ||
− | + | *''[[Eimeria spp.|Eimeria]] maxima'' | |
+ | **Mid-gut | ||
+ | **Thickening of walls | ||
+ | **Pink exudate | ||
− | + | *''[[Eimeria spp.|Eimeria]] tenella'' | |
+ | **Swollen [[Caecum - Anatomy & Physiology|caeca]] | ||
+ | **Thickening of wall | ||
+ | **Dark colouring containing a core of necrotic tissue and blood | ||
− | + | *Lesion scoring is the best method of diagnosing the severity of the lesions and therefore the causative ''[[Eimeria spp.|Eimeria]]'' species | |
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− | + | *''[[Eimeria spp.|Eimeria]] necatrix'' | |
+ | **Mid-gut | ||
+ | **Ballooning of wall | ||
+ | **White spots and petechiae forming 'salt and pepper' lesions | ||
+ | **Haemorrhage into lumen | ||
− | + | '''Immunity''' | |
+ | *Different ''[[Eimeria spp.|Eimeria]]'' species produce different levels of protective immunity | ||
+ | **''E.maxima'' -> ''E.brunetti'' and ''E.acervulina'' -> ''E.tenella'' and ''E.necatrix'' | ||
− | + | *There is no cross immunity between species | |
− | + | *There is very little passive immunity | |
− | + | *Evokes a cell-mediated response | |
− | + | *All ages of poultry are susceptible | |
− | + | '''Epidemiology''' | |
+ | *Oocysts are ubiquitous and robust | ||
+ | **Able to survive several months to years | ||
− | + | *It is impossible to keep buildings free from infection | |
− | + | **Chicks become infected by pecking the ground shortly after being placed in the poultry house | |
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− | + | *Biotic potential is enormous | |
+ | **Generation time is short | ||
+ | **Massive infections can build up rapidly | ||
+ | *Immunity develops relatively slowly | ||
+ | **With high stocking densities the situation is explosive | ||
− | + | '''Control''' | |
+ | *Chemical | ||
+ | **Intensive poultry production is largely dependent on the use of anticoccidial drugs | ||
+ | **For more information see [[Anti-Protozoal Drugs|here]] | ||
− | + | *[[Vaccines|Vaccines]] | |
+ | **Paracox | ||
+ | ***Multivalent attenuated [[Vaccines#What antigen(s) do we use in the vaccine?|live vaccine]] for replacement layers and broilers | ||
+ | ***Contains 7 live strains of ''[[Eimeria spp.|Eimeria]]'' | ||
+ | ***Lack the most pathogenic life cycle stage making the prepatent period shorter | ||
+ | ***Known as '''precocious''' strains | ||
+ | ***Chicks [[Vaccines|vaccinated]] on a single occasion when 1-9 days old through oocyst suspension in the feed or water | ||
+ | ***[[Vaccines|Vaccinated]] birds have sub-optimal growth rates so is not used for broilers | ||
+ | **Paracox 5 | ||
+ | ***Contains 5 strains of the most pathogenic ''[[Eimeria spp.|Eimeria]]'' | ||
+ | ***Used for broilers | ||
+ | ***Sprayed onto the first feed offered to new batches of chicks | ||
− | + | *Integrated control | |
+ | **Careful management is needed so in-feed prophylaxis and [[Vaccines|vaccination]] do not fail | ||
+ | **Remove litter and thoroughly clean houses in between crops | ||
+ | ***Optimum turn-around time is 10 days | ||
+ | **Use the lowest stocking density which is compatible with economic production | ||
+ | **Water bowls, roofs and walls should be well maintained to prevent litter becoming damp | ||
+ | **Stress factors should be avoided and adequate nutrition provided | ||
− | + | ==Literature Search== | |
+ | [[File:CABI logo.jpg|left|90px]] | ||
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− | + | Use these links to find recent scientific publications via CAB Abstracts (log in required unless accessing from a subscribing organisation). | |
− | <br>[ | + | <br><br><br> |
+ | [http://www.cabi.org/cabdirect/FullTextPDF/2009/20093257328.pdf '''Coccidiosis in poultry: review on diagnosis, control, prevention and interaction with overall gut health.''' Gussem, M. de; World's Poultry Science Association (WPSA), Beekbergen, Netherlands, World Poultry Science Association, Proceedings of the 16th European Symposium on Poultry Nutrition, Strasbourg, France, 26-30 August, 2007, 2007, pp 253-261, 36 ref. - '''Full Text Article'''] | ||
− | + | == Test yourself with the Coccidia Flashcards == | |
− | + | [[Coccidia Flashcards|Coccidia Flashcards]] | |
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− | + | [[Category:Coccidia]] [[Category:Alimentary_Diseases - Birds]] [[Category:To_Do_-_Clinical]] | |
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− | [[Category:Coccidia]] [[Category: |
Revision as of 16:52, 24 January 2011
Pathogenesis
- 7 important Eimeria species
- 4 malabsorptive species
- 3 haemorrhagic species
- Eimeria tenella
- Eimeria necatrix
- Eimeria brunetti
- All highly pathogenic
- Form large sub-epithelial second generation schizonts at the base of intestinal crypts
- Deep eruptions form when cells rupture to release merozoites
- Destruction of crypt stem cells and marked haemorrhage
- Blood stained faeces
- High morbidity and high mortality
Diagnosis
- Post-mortem diagnosis of lesion severity
- Region of intestine affected
- Appearance of lesion
- Presence or absence of haemorrhage
- Size of schizonts and oocysts found in mucosal scrapings
- Eimeria acervulina
- Proximal gut
- Thickening of walls
- 'White ladder lesions' produced by dense foci of gamonts and oocysts
- Watery exudate
- Eimeria maxima
- Mid-gut
- Thickening of walls
- Pink exudate
- Eimeria tenella
- Swollen caeca
- Thickening of wall
- Dark colouring containing a core of necrotic tissue and blood
- Lesion scoring is the best method of diagnosing the severity of the lesions and therefore the causative Eimeria species
- Eimeria necatrix
- Mid-gut
- Ballooning of wall
- White spots and petechiae forming 'salt and pepper' lesions
- Haemorrhage into lumen
Immunity
- Different Eimeria species produce different levels of protective immunity
- E.maxima -> E.brunetti and E.acervulina -> E.tenella and E.necatrix
- There is no cross immunity between species
- There is very little passive immunity
- Evokes a cell-mediated response
- All ages of poultry are susceptible
Epidemiology
- Oocysts are ubiquitous and robust
- Able to survive several months to years
- It is impossible to keep buildings free from infection
- Chicks become infected by pecking the ground shortly after being placed in the poultry house
- Biotic potential is enormous
- Generation time is short
- Massive infections can build up rapidly
- Immunity develops relatively slowly
- With high stocking densities the situation is explosive
Control
- Chemical
- Intensive poultry production is largely dependent on the use of anticoccidial drugs
- For more information see here
- Vaccines
- Paracox
- Multivalent attenuated live vaccine for replacement layers and broilers
- Contains 7 live strains of Eimeria
- Lack the most pathogenic life cycle stage making the prepatent period shorter
- Known as precocious strains
- Chicks vaccinated on a single occasion when 1-9 days old through oocyst suspension in the feed or water
- Vaccinated birds have sub-optimal growth rates so is not used for broilers
- Paracox 5
- Contains 5 strains of the most pathogenic Eimeria
- Used for broilers
- Sprayed onto the first feed offered to new batches of chicks
- Paracox
- Integrated control
- Careful management is needed so in-feed prophylaxis and vaccination do not fail
- Remove litter and thoroughly clean houses in between crops
- Optimum turn-around time is 10 days
- Use the lowest stocking density which is compatible with economic production
- Water bowls, roofs and walls should be well maintained to prevent litter becoming damp
- Stress factors should be avoided and adequate nutrition provided
Literature Search
Use these links to find recent scientific publications via CAB Abstracts (log in required unless accessing from a subscribing organisation).
Coccidiosis in poultry: review on diagnosis, control, prevention and interaction with overall gut health. Gussem, M. de; World's Poultry Science Association (WPSA), Beekbergen, Netherlands, World Poultry Science Association, Proceedings of the 16th European Symposium on Poultry Nutrition, Strasbourg, France, 26-30 August, 2007, 2007, pp 253-261, 36 ref. - Full Text Article