|
|
(48 intermediate revisions by 4 users not shown) |
Line 1: |
Line 1: |
− | {{unfinished}}
| + | #REDIRECT[[:Category:Coccidia]] |
− | | |
− | {{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 28x20μm
| |
− | **Moderately pathogenic
| |
− | | |
− | *''Eimeria zuernii''
| |
− | **Endogenous stages in connective tissue of lamina propria of the lower small intestine and in the epithelial cells of the caecum and colon
| |
− | **More pathogenic than ''Eimeria bovis''
| |
− | **Causes blood stained dysentry, tenesmus and sloughed mucosa
| |
− | **Oocysts are spherical and measure 16μm
| |
− | | |
− | *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
| |