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− | ==Introduction==
| + | #REDIRECT[[:Category:Coccidia]] |
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− | [[Image:Coccidia.jpg|thumb|right|150px|Coccidia - Joel Mills]]
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− | *The '''oocyst''' is the resistant stage in the environment
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− | *The infective '''sporozoite''' is released from the oocyst
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− | *Inside the host, the sporozoites invade the intestinal epithelial tissue
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− | **Sporozoites feed and grow
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− | *As the sporozoite grows the nucleus divides forming a '''schizont'''
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− | *The schizont contains numerous elongated '''merozoites'''
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− | *The formation of merozoites is the first asexual reproductive stage called '''schizogony'''
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− | *The schizont ruptures releasing the merozoites which also invade the epithelial cells
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− | *Another generation of schizonts form which is the beginning of the sexual phase of reproduction called '''gametogony'''
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− | *The merozoites form male '''microgamonts''' or female '''macrogamonts'''
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− | **Collectively known as gamonts or gametocytes
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− | *The microgamonts released from the microgametocyte penetrate and fertilise the macrogamont (which is contained within the macrogametocyte)
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− | *Gametogony forms the '''zygote'''
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− | **Surrounded by a cyst wall
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− | **Forms the '''oocyst'''
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− | *The oocyst is passed in the faeces and is unsporulated
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− | *The oocyst becomes sporulated in the second asexual reproductive phase called '''sporogony'''
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− | *Once the oocyst is sporulated it is infective
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− | <big>
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− | '''[[Eimeria spp.|''Eimeria'' spp.]]
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− | '''[[Isospora spp.|''Isospora'' spp.]]
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− | '''[[Coccidiosis]]
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− | '''[[Coccidia - Poultry|Coccidia of Poultry]]
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− | '''[[Coccidiosis - Poultry]]
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− | '''[[Coccidiosis - Turkey|Coccidia of Turkeys]]
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− | '''[[Coccidiosis - Geese|Coccidia of Geese]]
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− | '''[[Coccidiosis - Duck|Coccidia of Ducks]]
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− | '''[[Coccidiosis - Game Birds|Coccidia of Game Birds]]
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− | '''[[Coccidiosis - Cattle|Coccidia of Cattle]]
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− | '''[[Coccidiosis - Sheep|Coccidia of Sheep]]
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− | ==Coccidia of Goats==
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− | [[Image:Goats.jpg|thumb|right|150px|Goats - nabrown RVC]]
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− | [[Image:Eimeria leukarti horse.jpg|thumb|right|150px|''Eimeria leukarti'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
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− | [[Image:Isospora suis oocyst.jpg|thumb|right|150px|''Isospora suis'' oocyst from pig faeces - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
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− | [[Image:Isospora canis.jpg|thumb|right|150px|''Isospora canis'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]] | |
− | [[Image:Coccidia.jpg|thumb|right|150px|Coccidia in Cat Faeces - Joel Mills]]
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− | [[Image:Isospora felis.jpg|thumb|right|150px|''Isospora felis'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
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− | *Many ''Eimeria'' species
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− | *2 ''Eimeria'' are pathogenic
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− | **Cause [[Intestine Diarrhoea - Pathology|diarrhoea]] and a decreased growth rate
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− | *Different species of ''Eimeria'' occurs in sheep and goats
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− | ==Coccidia of Horses==
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− | *Only one atypical ''Eimeria''
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− | *Forms large subepithelial gametocytes in villi
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− | *Large, dark coloured oocysts
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− | **Approximately 12μm
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− | *Occasionally causes [[Intestine Diarrhoea - Pathology|diarrhoea]]
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− | *''Besnoitia bennetti'' in [[Respiratory Parasitic Infections - Pathology#Besnoitia bennetti|larynx]] of horses
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− | ==Coccidia of Pigs==
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− | *Many species of ''Eimeria'' and ''Isospora''
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− | *Only ''Isospora suis'' is of clinical pathogenic importance
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− | *Causes sporadic, serious and sometimes fatal disease in unweaned piglets
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− | **Causes profuse [[Intestine Diarrhoea - Pathology|diarrhoea]]
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− | *Very short 1 week prepatent period
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− | *[[Intestine Diarrhoea - Pathology|Diarrhoea]] starts before oocysts are shed in faeces
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− | **Ante-mortem diagnosis is difficult
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− | *Death usually occurs after parasites have left the host
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− | **Post-mortem diagnosis difficult
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− | **''Isospora'' infections are '''self-limiting'''
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− | ==Coccidia of Dogs==
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− | *2 common and 2 less common ''Isospora'' species
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− | *Occasionally can cause disease
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− | *Little pathogenicity
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− | *Even if faecal oocyst count is high, other causes of [[Intestine Diarrhoea - Pathology|diarrhoea]] should be looked for
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− | *''Hepatozoon americanum'' and subclinical ''H. canis'' in [[Bones Hyperplastic and Neoplastic - Pathology#Hepatozoon|periosteal bone formation]]
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− | **Both are Tick borne diseases
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− | ***''H. canis'' – ''Rhipicephalus sanguineus''
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− | ***Ticks become infected by ingesting a blood meal containing macrophages and [[Neutrophils - WikiBlood|neutrophils]] infected with the parasite gamonts -> sexual replication in the gut of the tick -> oocysts containing infective sporozoites -> dogs ingest the tick schizogony occurs in numerous tissues
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− | ==Coccidia of Cats==
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− | *2 common ''Isospora'' species with little clinical significance
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− | *Oocysts in faeces have to be distinguised from those of ''Toxoplasma'' (smaller) and ''Sarcocytis'' (sporulated or naked sporocyts in faeces)
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− | ==Coccidia of Rabbits==
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− | *3 pathogenic ''Eimeria'' species
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− | **2 in the [[Caecum - Anatomy & Physiology|caecum]]
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− | **1 in the bile duct
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− | *''Eimeria steidae''
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− | **Parasitises the bile duct epithelium
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− | **Travels via the bile duct to the [[Liver - Anatomy & Physiology|liver]] where it forms large white nodules
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− | **Oocysts travel in the bile and are passed out in the faeces
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− | **Causes ascites, [[Intestine Diarrhoea - Pathology|diarrhoea]], weight loss and polyuria
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− | *Serious disease of both pet and farmed rabbits
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− | *Treatment is by administration of drugs in drinking water
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− | **E.g. Toltrazuril
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− | *Hygiene is the best method of prevention to prevent sporocysts from sporulating
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− | *Medicated feed can be used in commercial units
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− | **E.g. Rabenidine
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− | ==[[Protozoa Flashcards - Wikibugs#Coccidia|Coccidia Flashcards]]==
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− | [[Category:Coccidia]]
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