Difference between revisions of "Coccidia"
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− | # | + | {{unfinished}} |
+ | |||
+ | {{toplink | ||
+ | |backcolour = | ||
+ | |linkpage =Parasites | ||
+ | |linktext =PARASITES | ||
+ | |pagetype=Bugs | ||
+ | |sublink1=Protozoa | ||
+ | |subtext1=PROTOZOA | ||
+ | }} | ||
+ | <br> | ||
+ | ==''Eimeria'' spp.== | ||
+ | |||
+ | ==''Isospora'' spp.== | ||
+ | |||
+ | ==Coccidia of Poultry== | ||
+ | |||
+ | ==Other Avian Coccidia== | ||
+ | |||
+ | ==Coccidia of Cattle== | ||
+ | *Many species affect cattle | ||
+ | |||
+ | *Cattle under a year old are usually infected sporadically | ||
+ | |||
+ | *2-3 week prepatent period | ||
+ | |||
+ | *''Eimeria bovis'' | ||
+ | **Endogenous stages in central lacteal of villi and epithelial cells of caecum and colon | ||
+ | **Causes [[Intestine Diarrhoea - Pathology|diarrhoea]] and enteritis | ||
+ | **Oocysts are 28x20m | ||
+ | |||
+ | *''Eimeria zuernii'' | ||
+ | |||
+ | *Mainly occurs in calves in poor conditions and brought-in calves | ||
+ | **Also occurs in suckler calves turned out in spring | ||
+ | |||
+ | *''Eimeria alabamensis'' associated with [[Intestine Diarrhoea - Pathology|diarrhoea]] in calves after spring turnout | ||
+ | |||
+ | *[[Materno-fetal immunity - WikiBlood#Passive transfer via colostrum|Passive immunity]] is sufficient during the neonatal period | ||
+ | |||
+ | *Can be concurrent with cryptosporidium, viral and bacterial agents | ||
+ | |||
+ | '''Diagnosis''' | ||
+ | *History, clinical signs, [[Intestine Diarrhoea - Pathology|diarrhoea]] (often with blood) and a decrease in weight gain | ||
+ | |||
+ | *Post-mortem | ||
+ | **Diffuse inflammation and thickening of caecal mucosa (and sometimes ileal and colonic mucosa) | ||
+ | **Masses of gamonts and oocysts in scrapings | ||
+ | |||
+ | *High faecal oocyst count | ||
+ | **However, healthy animals can pass millions of oocysts from mixed species infections which have no pathogenic significance | ||
+ | **Animals may die before oocysts are shed | ||
+ | |||
+ | '''Control''' | ||
+ | *Improve husbandry | ||
+ | **Improve sanitation | ||
+ | **Increase bedding | ||
+ | **Raise faecal and water troughs to avoid faecal contamination | ||
+ | |||
+ | *Preventative in-feed medication | ||
+ | **E.g. Decoquinate | ||
+ | |||
+ | *Injectible antiprotozoals may limit oocyst production but animals should still be moved to a clean environment | ||
+ | **E.g. Sulphamethoxypyridazine | ||
+ | |||
+ | ==Coccidia of Sheep== | ||
+ | *11 different Coccidia species although only two are of clinical significance | ||
+ | **Giant schizonts visible as white spots | ||
+ | |||
+ | *''Eimeria ovinoidalis'' | ||
+ | **Highly pathogenic | ||
+ | **[[Intestine Diarrhoea - Pathology|Diarrhoea]] | ||
+ | **Parasitises the [[Caecum - Anatomy & Physiology|caecum]] and [[Colon - Anatomy & Physiology|colon]] | ||
+ | |||
+ | *''Eimeria crandalis'' | ||
+ | **Varying pathogenicity | ||
+ | **Scours, grey, foul-smelling faeces | ||
+ | **Parasitises the [[Small Intestine - Anatomy & Physiology|small intestine]], [[Caecum - Anatomy & Physiology|caecum]] and [[Colon - Anatomy & Physiology|colon]] | ||
+ | |||
+ | *2 week prepatent period | ||
+ | |||
+ | *Disease frequently seen in lambs under 6 months old | ||
+ | **More often in twins and triplets when single lambs | ||
+ | |||
+ | *Oocyts from ewes (immune carriers) accumulate in poorly managed litter or around feed and water troughs | ||
+ | |||
+ | *Lambs born early in the year amplify the parasite problem increasing the parasite risk to lambs born later in the year | ||
+ | |||
+ | *Affected lambs may die before oocysts are found in the faeces | ||
+ | **Post-mortem diagnosis difficult | ||
+ | |||
+ | *Different species of ''Eimeria'' occurs in sheep and goats | ||
+ | |||
+ | *Infection may be coincident with ''Neospora'' or ''Cryptosporidium'' infections | ||
+ | **Mixed infections complicate the diagnosis as oocyst differentiation is difficult | ||
+ | |||
+ | *Other non-pathogenic species can cause papillomatous mucosal growths | ||
+ | |||
+ | '''Control''' | ||
+ | *Improve husbandry | ||
+ | **Avoid overcrowding | ||
+ | **Decrease stress | ||
+ | |||
+ | *Improve hygiene by dagging ewes | ||
+ | |||
+ | *Avoid mixing lambs of different ages | ||
+ | |||
+ | *Preventative measures include creep feeding lambs with decoquinate or oral dosing with diclazuril when lambs are 4-6 weeks | ||
+ | **A second dose can be given after 3 weeks | ||
+ | |||
+ | ==Coccidia of Goats== | ||
+ | *Many ''Eimeria'' species | ||
+ | |||
+ | *2 ''Eimeria'' are pathogenic | ||
+ | **Cause [[Intestine Diarrhoea - Pathology|diarrhoea]] and a decreased growth rate | ||
+ | |||
+ | *Different species of ''Eimeria'' occurs in sheep and goats | ||
+ | |||
+ | ==Coccidia of Horses== | ||
+ | *Only one atypical ''Eiemria'' | ||
+ | |||
+ | *Forms large subepithelial gametocytes in villi | ||
+ | |||
+ | *Large, dark coloured oocysts | ||
+ | **Approximately 12μm | ||
+ | |||
+ | *Occasionally causes [[Intestine Diarrhoea - Pathology|diarrhoea]] | ||
+ | |||
+ | *''Besnoitia bennetti'' in [[Respiratory Parasitic Infections - Pathology#Besnoitia bennetti|larynx]] of horses | ||
+ | |||
+ | ==Coccidia of Pigs== | ||
+ | *Many species of ''Eimeria'' and ''Isospora'' | ||
+ | |||
+ | *Only ''Isospora suis'' is of clinical pathogenic importance | ||
+ | |||
+ | *Causes sporadic, serious and sometimes fatal disease in unweaned piglets | ||
+ | **Causes profuse [[Intestine Diarrhoea - Pathology|diarrhoea]] | ||
+ | |||
+ | *Very short 1 week prepatent period | ||
+ | |||
+ | *[[Intestine Diarrhoea - Pathology|Diarrhoea]] starts before oocysts are shed in faeces | ||
+ | **Ante-mortem diagnosis is difficult | ||
+ | |||
+ | *Death usually occurs after parasites have left the host | ||
+ | **Post-mortem diagnosis difficult | ||
+ | **''Isospora'' infections are '''self-limiting''' | ||
+ | |||
+ | ==Coccidia of Dogs== | ||
+ | *2 common and 2 less common ''Isospora'' species | ||
+ | |||
+ | *Occasionally can cause disease | ||
+ | |||
+ | *Little pathogenicity | ||
+ | |||
+ | *Even if faecal oocyst count is high, other causes of [[Intestine Diarrhoea - Pathology|diarrhoea]] should be looked for | ||
+ | |||
+ | *''Hepatozoon americanum'' and subclinical ''H. canis'' in [[Bones Hyperplastic and Neoplastic - Pathology#Hepatozoon|periosteal bone formation]] | ||
+ | **Both are Tick borne diseases | ||
+ | ***''H. canis'' – ''Rhipicephalus sanguineus'' | ||
+ | ***Ticks become infected by ingesting a blood meal containing macrophages and 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 | ||
+ | |||
+ | |||
+ | ==Coccidia of Cats== | ||
+ | [[Image:Coccidia.jpg|thumb|right|150px|Coccidia in Cat Faeces - Joel Mills]] | ||
+ | *2 common ''Isospora'' species with little clinical significance | ||
+ | |||
+ | *Oocysts in faeces have to be distinguised from those of ''Toxoplasma'' (smaller) and ''Sarcocytis'' (sporulated or naked sporocyts in faeces) | ||
+ | |||
+ | ==Coccidia of Rabbits== | ||
+ | *3 pathogenic ''Eimeria'' species | ||
+ | **2 in the caecum | ||
+ | **1 in the bile duct | ||
+ | |||
+ | *''Eimeria steidae'' | ||
+ | **Parasitises the bile duct epithelium | ||
+ | **Travels via the bile duct to the liver where it forms large white nodules | ||
+ | **Oocysts travel in the bile and are passed out in the faeces | ||
+ | **Causes ascites, [[Intestine Diarrhoea - Pathology|diarrhoea]], weight loss and polyuria | ||
+ | |||
+ | *Serious disease of both pet and farmed rabbits | ||
+ | |||
+ | *Treatment is by administration of drugs in drinking water | ||
+ | **E.g. Toltrazuril | ||
+ | |||
+ | *Hygiene is the best method of prevention to prevent sporocysts from sporulating | ||
+ | |||
+ | *Medicated feed can be used in commercial units | ||
+ | **E.g. Rabenidine |
Revision as of 21:32, 15 November 2008
This article is still under construction. |
|
Eimeria spp.
Isospora spp.
Coccidia of Poultry
Other Avian Coccidia
Coccidia of Cattle
- Many species affect cattle
- Cattle under a year old are usually infected sporadically
- 2-3 week prepatent period
- Eimeria bovis
- Endogenous stages in central lacteal of villi and epithelial cells of caecum and colon
- Causes diarrhoea and enteritis
- Oocysts are 28x20m
- Eimeria zuernii
- Mainly occurs in calves in poor conditions and brought-in calves
- Also occurs in suckler calves turned out in spring
- Eimeria alabamensis associated with diarrhoea in calves after spring turnout
- Passive immunity is sufficient during the neonatal period
- Can be concurrent with cryptosporidium, viral and bacterial agents
Diagnosis
- History, clinical signs, diarrhoea (often with blood) and a decrease in weight gain
- Post-mortem
- Diffuse inflammation and thickening of caecal mucosa (and sometimes ileal and colonic mucosa)
- Masses of gamonts and oocysts in scrapings
- High faecal oocyst count
- However, healthy animals can pass millions of oocysts from mixed species infections which have no pathogenic significance
- Animals may die before oocysts are shed
Control
- Improve husbandry
- Improve sanitation
- Increase bedding
- Raise faecal and water troughs to avoid faecal contamination
- Preventative in-feed medication
- E.g. Decoquinate
- Injectible antiprotozoals may limit oocyst production but animals should still be moved to a clean environment
- E.g. Sulphamethoxypyridazine
Coccidia of Sheep
- 11 different Coccidia species although only two are of clinical significance
- Giant schizonts visible as white spots
- Eimeria crandalis
- Varying pathogenicity
- Scours, grey, foul-smelling faeces
- Parasitises the small intestine, caecum and colon
- 2 week prepatent period
- Disease frequently seen in lambs under 6 months old
- More often in twins and triplets when single lambs
- Oocyts from ewes (immune carriers) accumulate in poorly managed litter or around feed and water troughs
- Lambs born early in the year amplify the parasite problem increasing the parasite risk to lambs born later in the year
- Affected lambs may die before oocysts are found in the faeces
- Post-mortem diagnosis difficult
- Different species of Eimeria occurs in sheep and goats
- Infection may be coincident with Neospora or Cryptosporidium infections
- Mixed infections complicate the diagnosis as oocyst differentiation is difficult
- Other non-pathogenic species can cause papillomatous mucosal growths
Control
- Improve husbandry
- Avoid overcrowding
- Decrease stress
- Improve hygiene by dagging ewes
- Avoid mixing lambs of different ages
- Preventative measures include creep feeding lambs with decoquinate or oral dosing with diclazuril when lambs are 4-6 weeks
- A second dose can be given after 3 weeks
Coccidia of Goats
- Many Eimeria species
- 2 Eimeria are pathogenic
- Cause diarrhoea and a decreased growth rate
- Different species of Eimeria occurs in sheep and goats
Coccidia of Horses
- Only one atypical Eiemria
- Forms large subepithelial gametocytes in villi
- Large, dark coloured oocysts
- Approximately 12μm
- Occasionally causes diarrhoea
- Besnoitia bennetti in larynx of horses
Coccidia of Pigs
- Many species of Eimeria and Isospora
- Only Isospora suis is of clinical pathogenic importance
- Causes sporadic, serious and sometimes fatal disease in unweaned piglets
- Causes profuse diarrhoea
- Very short 1 week prepatent period
- Diarrhoea starts before oocysts are shed in faeces
- Ante-mortem diagnosis is difficult
- Death usually occurs after parasites have left the host
- Post-mortem diagnosis difficult
- Isospora infections are self-limiting
Coccidia of Dogs
- 2 common and 2 less common Isospora species
- Occasionally can cause disease
- Little pathogenicity
- Even if faecal oocyst count is high, other causes of diarrhoea should be looked for
- Hepatozoon americanum and subclinical H. canis in periosteal bone formation
- Both are Tick borne diseases
- H. canis – Rhipicephalus sanguineus
- Ticks become infected by ingesting a blood meal containing macrophages and 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
- Both are Tick borne diseases
Coccidia of Cats
- 2 common Isospora species with little clinical significance
- Oocysts in faeces have to be distinguised from those of Toxoplasma (smaller) and Sarcocytis (sporulated or naked sporocyts in faeces)
Coccidia of Rabbits
- 3 pathogenic Eimeria species
- 2 in the caecum
- 1 in the bile duct
- Eimeria steidae
- Parasitises the bile duct epithelium
- Travels via the bile duct to the liver where it forms large white nodules
- Oocysts travel in the bile and are passed out in the faeces
- Causes ascites, diarrhoea, weight loss and polyuria
- Serious disease of both pet and farmed rabbits
- Treatment is by administration of drugs in drinking water
- E.g. Toltrazuril
- Hygiene is the best method of prevention to prevent sporocysts from sporulating
- Medicated feed can be used in commercial units
- E.g. Rabenidine