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| | + | |pagetitle =Enteritis, Fibrinous/Haemorrhagic |
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| | + | <categorytree mode=pages>Enteritis, Fibrinous/Haemorrhagic</categorytree> |
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| | ==Pathology== | | ==Pathology== |
| | | | |
| | * The mucosa eroded to produce lesions of darkish-red submucosa covered in dry, crumbly fibrin. | | * The mucosa eroded to produce lesions of darkish-red submucosa covered in dry, crumbly fibrin. |
| | * Is usually caused by severe damage due to secondary bacterial infection following an earlier milder insult. | | * Is usually caused by severe damage due to secondary bacterial infection following an earlier milder insult. |
| − | * Tends to be more severe in the lower [[Small Intestine - Anatomy & Physiology|small intestine]] and upper [[Large Intestine - Anatomy & Physiology|large intestine]]. | + | * Tends to be more severe in the lower [[Small Intestine Overview - Anatomy & Physiology|small intestine]] and upper [[Large Intestine - Anatomy & Physiology|large intestine]]. |
| | ** Many severe infections tend to get worse further down the gut. | | ** Many severe infections tend to get worse further down the gut. |
| − | *** Catarrhal change may be seen in the upper [[Small Intestine - Anatomy & Physiology|small intestine]] and fibrinous change in the lower [[Small Intestine - Anatomy & Physiology|small intestine]]s. | + | *** Catarrhal change may be seen in the upper [[Small Intestine Overview - Anatomy & Physiology|small intestine]] and fibrinous change in the lower [[Small Intestine Overview - Anatomy & Physiology|small intestine]]s. |
| | ** In the lower aprt of the bowel, where the inflammation is more severe, disease is more anaerobic. | | ** In the lower aprt of the bowel, where the inflammation is more severe, disease is more anaerobic. |
| | *** Lesions are caused by anaerobic organisms- convert mild diseases into more serious disease. | | *** Lesions are caused by anaerobic organisms- convert mild diseases into more serious disease. |
| | | | |
| − | ==Salmonellosis==
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| − |
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| − | * There are many different serotypes of [[Salmonella|''Salmonella'']].
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| − | ** All can produce disease BUT only a few commonly produce illness in UK.
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| − | ** ''Salmonella'' poses a serious risk to man.
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| − | ** Some serotypes tend to be more species specific, whereas others can affect a wide range of species. For example:
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| − | *** [[Salmonella|'''''Salmonella enteritidis''''']]
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| − | *** [[Salmonella|'''''Salmonella typhimurium''''']]
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| − | **** Widespread in most species.
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| − | *** [[Salmonella|''''' Salmonella dublin''''']]
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| − | **** Cattle
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| − | *** [[Salmonella|'''''Salmonella cholerae suis''''']]
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| − | **** Pigs
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| − | **** Usually speticaemic.
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| − | **** Not very common now.
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| − | *** [[Salmonella|'''''Salmonella montevideo''''']]
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| − | **** Produces outbreaks from contaminated imported meat and bone meal.
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| − | ** Strains are often named after where they were first isolated.
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| − | ** Typing is important for epidemiology.
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| − | ** All strains can occur epizootically, enzootically and sporadically.
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| − | ** All strains can also produce very similar changes.
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| − | * Salmonellosis is NOT very common in the dog and cat.
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| − | * However, the horse is often a carrier.
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| − | ** Stress may precipitate the disease, meaning Salmonellosis is seen often in veterinary hospitals.
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| − |
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| − | ===Pathogenesis===
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| − |
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| − | * Disease is often seen associated with stress.
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| − | * organisms penetrate enterocytes before crossing the mucosa and entering macrophages.
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| − | ** After entering macrophages, organins may then either remain localised to the gut, or are carried round the body to cause disease.
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| − | * There are 2 main types of disease- '''septicaemic''' and '''enteric'''.
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| − | ** Each outbreak causes only one type of disease.
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| − | ** Type of disease is linked to serotype- some serotyopres produce septicaemia, whereas others remain localised in the gut.
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| − |
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| − |
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| − | ====Septicaemic Salmonellosis====
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| − |
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| − | * Septicaemic salmonellosis is very dramatic and produces death quite suddenly.
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| − | * [[Intestine Diarrhoea - Pathology|diarrhoea]] is often not seen before death.
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| − | * This form of the disease is unusual in the very young.
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| − |
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| − | =====Pathogenesis=====
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| − |
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| − | * The organism [[Colon - Anatomy & Physiology|colon]]ises bowel epithelium, where it affects the [[Peyer's Patches - Anatomy & Physiology|Peyers patches]].
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| − | ** It then invades macrophages, which enable it to invade across the epithelium to the submucosa. It may then either
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| − | *** Remain localised to submucosa, or
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| − | *** Spread to the lymph nodes and enter the circulation to become septicaemic.
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| − | * Animals may die at this stage (30%), but this depends on such factors as the infecting dose and strain.
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| − | * Is similar to septicaemic[[Escherichia coli|'' E. Coli'']].
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| − |
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| − | =====Clinical=====
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| − |
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| − | * Is usually post-weaning (is unusual in the very young animal).
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| − | ** 6 to 9 months in calves.
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| − | ** 6 to 10 weeks in piglets.
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| − | * Animals suffer from pyrexia, and occasionally a little bit of [[Intestine Diarrhoea - Pathology|diarrhoea]].
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| − | * Skin is reddened diffusely
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| − | ** Bruise-like dark purplish-red blotched may be seen.
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| − |
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| − | =====Pathology=====
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| − |
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| − | * Intestines
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| − | ** May show mild catarrhal enteritis, becoming fibrinous lower down.
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| − | ** The bowel is generally flaccid, reddened and filled with fluid.
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| − | ** Ecchymotic and petechial haemorrhages on serosa and mucosa.
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| − | ** Enlarged, haemorrhagic mesenteric lymph nodes.
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| − | * Excessive blood-tinged peritoneal fluid.
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| − | * Lungs are collapsed and frothy.
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| − | * Heart is often dilated with ecchymotic haemorrhages.
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| − | * Viscera have a "half-cooked appearance"
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| − | ** Pale in colour.
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| − | ** The [[Liver - Anatomy & Physiology|liver]] and kidneys are also flabby and may have subcapsular haemorrhages.
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| − | ** The [[Liver - Anatomy & Physiology|liver]] may contain small white foci of necrosis known as '''paratyphoid granulomas'''.
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| − |
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| − | =====Diagnosis=====
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| − |
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| − | * By culture of blood and from mesenteric lymph nodes (which are oedematous and red).
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| − |
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| − |
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| − | ====Enteric Salmonellosis====
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| − |
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| − | * Enteric Salmonellosis shows differences in clinical presentation between species.
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| − | ** '''Horse''' - acute fatal colitis.
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| − | ** '''Cows''' - lingering febrile [[Intestine Diarrhoea - Pathology|diarrhoea]] with passage of pseudomembranes.
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| − | ** '''Calves''' - acute [[Intestine Diarrhoea - Pathology|diarrhoea]] like colibacillosis.
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| − | ** '''Dogs''' - acute bouts of [[Intestine Diarrhoea - Pathology|diarrhoea]].
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| − | ** '''Cats''' - febrile enterocolitis.
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| − | ** '''Pigs''' - septicemia or enterocolitis.
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| − |
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| − | =====Clinical=====
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| − |
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| − | * Affected animals produce acute [[Intestine Diarrhoea - Pathology|diarrhoea]], which causes many deaths.
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| − | ** Watery and yellow.
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| − | ** May be tinged with a little blood.
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| − | * Animals may die from dehydration.
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| − | * In some outbreaks, particularly in pigs, chronic low-grade [[Intestine Diarrhoea - Pathology|diarrhoea]] only is seen.
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| − | * Calves usually die in acute stage, but may also recover.
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| − |
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| − | =====Pathology=====
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| − |
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| − | * Enteritis is seen throughout the gut, but is worse further along the gut.
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| − | ** Inflammation is catarrhal in the [[Duodenum - Anatomy & Physiology|duodenum]].
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| − | ** By the ileocaecal junction enteritis is often fibrinous, sometimes with formation of diptheric membranes on the mucosal surface.
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| − | * The necrotic and fibrinous changes particularly affect the Peyers patches and the caecal and [[Colon - Anatomy & Physiology|colon]]ic lymphoid nodules.
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| − | ** May lead to "button ulcers" in the terminal [[Ileum - Anatomy & Physiology|ileum]] and [[Colon - Anatomy & Physiology|colon]].
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| − | *** These ulcers rupture very rarely.
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| − | * Focal necrosis may also be seen.
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| − | ** Particularly in the [[Liver - Anatomy & Physiology|liver]], but also in the [[Spleen - Anatomy & Physiology|spleen]].
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| − | ** Histologically, foci show a central zone of necrosis, surrounded by macrophages and lymphocytes- [[Intestine Inflammatory - Pathology#Septicaemic Salmonellosis|paratyphoid granulomas]].
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| − | *** Although this indicates the animal has had a systemic incfection, paratyphoid granulomas may be present without showing signs of septicaemia.
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| − | *** Enteric cases of salmonella infection nearly always show some evidence of systemic spread.
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| − | * Septicaemic form may relocalise in the gut, resulting in enteric disease.
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| − |
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| − | =====Sequelae=====
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| − |
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| − | * Animals can remain carriers for months/years following recovery from the acute [[Intestine Diarrhoea - Pathology|diarrhoea]] phase.
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| − | ** Bacteria is shed from the bile duct and mesenteric lymph nodes.
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| − | *** A source of infection for other animals and people.
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| − | *** Shed particularly in times of stress.
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| − | * '''Stricture of the [[Rectum - Anatomy & Physiology|rectum]]'''.
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| − | ** A possible sequel to acute salmonellosis, especially in the piglet.
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| − | ** Just a few centimetres in from the [[[[Anus - Anatomy & Physiology|anus]] - Anatomy & Physiology|[[Anus - Anatomy & Physiology|anus]]]].
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| − | ** Gives rise to:
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| − | **# Difficulty in passing faeces.
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| − | **# Mega[[Colon - Anatomy & Physiology|colon]]
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| − | **# thin watery [[Intestine Diarrhoea - Pathology|diarrhoea]] in small 'pencils'.
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| − | **# blown up abdomen
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| − | ** Animals eventually die from the stricture if they are not first destroyed.
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| − |
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| − | ==Swine Dysentery==
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| − |
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| − | * Swine dysentery gives rise to fibrinous/ haemorrhagic enteritis.
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| − | * A quite common and important disease.
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| − | * The disease is caused by [[Brachyspira hyodysenteriae|''Brachyspira hyodysenteriae'']].
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| − | ** Is not seen in gnotobiotic animals - other enteric pathogens such as [[Fusobacterium|''Fusobacterium'']] or [[Bacteroides|''Bacteroides'']] may therefore also be required in order to produce disease.
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| − | * The disease is NOT systemic.
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| − | ** Localised to the [[Large Intestine - Anatomy & Physiology|large intestine]]- in particular, the spiral [[Colon - Anatomy & Physiology|colon]].
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| − | * Swine dysentery is spread by the faeco-oral route, and is carried by pigs and rodents.
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| − |
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| − | ===Clinical===
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| − |
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| − | * Affects post weaning pigs at approximately 4 months of age.
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| − | * White scour becomes a liquid dirty red / brown scour with a foul smell.
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| − | ** Contains poorly digested focal shreds of mucosa and fibrin strands.
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| − | *** '''Mucoid covered faeces'''.
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| − | * There are three outcomes to infection; the animal may:
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| − | ** Die
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| − | ** There is a morbidity up to 90% in the herd, with up to 50% mortality.
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| − | ** Recover
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| − | ** Become chronically infected.
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| − | * Symptoms are due to loss of absorption in [[Colon - Anatomy & Physiology|colon]].
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| − | ** The [[Colon - Anatomy & Physiology|colon]] is normally a key site of absorption for water and electrolytes in the pig.
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| − |
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| − | ===Pathology===
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| − |
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| − | * The serosa of the spiral [[Colon - Anatomy & Physiology|colon]] may appear shiny from the outside.
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| − | ** Is turgid and oedematous.
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| − | ** In severe cases, haemorrhage may be seen.
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| − | * The [[Small Intestine - Anatomy & Physiology|small intestine]] NOT affected.
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| − | * Fibrinous deposits are seen on the mucosa as the disease progresses.
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| − | ** The mucosa underneath is eroded to expose blood vessels in lamina propria.
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| − | *** Accounts for the bleeding.
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| − | * Animals often recover, but have a low feed conversion ratio for sometime.
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| − |
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| − | ===Diagnosis===
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| − |
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| − | * Silver stains show organisms in the epithelium of the mucosa.
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| − | * Also by immunofluorescence or electron microscopy.
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| − |
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| − | ==Parvovirus Enteritis==
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| − |
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| − | * [[Parvoviridae|Parvovirus]] enteritis is also know as feline infectious enteritis or feline panleucopenia
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| − | * Since a vaccine is available, this disease is now uncommon.
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| − | * Over the last 10/15 years this has been seen primarily in the cat, but it is now also seen [[Intestine Inflammatory - Pathology#Canine Disease|in the dog]].
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| − |
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| − | ===Clinical===
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| − |
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| − | * Manifests mainly in cats under 6 months old.
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| − | * Common in groups of unvaccinated cats.
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| − | ** Produces big outbreaks, with [[Control of Feeding - Anatomy & Physiology#The Vomit Reflex|vomiting]] and pyrexia.
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| − | * Severe [[Control of Feeding - Anatomy & Physiology#The Vomit Reflex|vomiting]] and [[Intestine Diarrhoea - Pathology|diarrhoea]] occur.
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| − | ** [[Intestine Diarrhoea - Pathology|diarrhoea]] is thin, watery and foul-smelling, and may also be blood-tinged.
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| − | *** Animals usually die despite treatment- die from dehydration.
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| − | * Animals suffer from fever.
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| − | * Pancytopaenia also occures.
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| − | ** White blood cell count drops very low so as to become almost non-existent.
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| − | *** Drops to 1/ml from 10000/ml.
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| − | ** Animals may therefore also die from other infections.
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| − |
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| − | ===Pathology===
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| − |
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| − | ====Gross====
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| − |
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| − | * Virus targets crypt cells and lymphoid areas.
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| − | ** Causes [[Intestine Inflammatory - Pathology#Villus Atrophy|villus atrophy]].
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| − | * In the cat, the intestine is thickened, turgid and swollen.
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| − | ** Has a pale, dull and mottled appearance.
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| − | ** The contents are rather dry - this gets worse lower down the gut.
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| − | * Areas of depression in the mucosa can be seen in the upper small bowel.
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| − | ** Due to necrosis of tissue overlying Peyers patch.
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| − | * Lower down in the gut, enteritis is apparent.
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| − | ** Cat- fibrinous.
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| − | ** Dog- haemorrhagic.
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| − | *** Blood in lumen.
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| − | ** Inflammation sometimes doesn't appear very severe.
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| − | * There may be very few lesions
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| − | ** Histology is usually required for diagnosis.
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| − | * A '''radiomimetic virus'''.
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| − | ** Affects all rapidly dividing cells and destroys them.
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| − | *** E.g. epithelium in the base of the crypts of [[Small Intestine - Anatomy & Physiology|small intestine]] are killed.
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| − |
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| − | ====Histological====
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| − |
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| − | * The crypt lining cells undergo complete necrosis, but very little inflammation occurs.
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| − | ** Collapse of villous architecture.
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| − | * May be fibrinous exudates on surface of mucosa.
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| − | * The submucosa and lamina propria are not affected and are left intact.
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| − | ** Many [[Neutrophils - WikiBlood|neutrophils]] in the lamina propria.
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| − | * Cyst-like structures are seen in the deepest parts of the glands of the intestinal mucosa, if the animal survives for more than a few days.
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| − | ** Flattened epithelial cells line these cystic glands.
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| − | *** Are enterocytes trying to repair the damage.
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| − | *** However, animals usually die from dehydration or secondary infection before the mucosa recovers.
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| − | * Inclusion bodies may be seen, but these are very hard to find.
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| − | * May get [[Lymphocytes - WikiBlood|lymphocyte]] invasion of mucosa.
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| − | * [[Lymph Nodes - Anatomy & Physiology|Lymph nodes]] appear pale and oedematous, and almost aplastic.
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| − | * [[Bone Marrow - Anatomy & Physiology|Bone marrow]] appears pale and fatty looking and is depleted of cells.
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| − |
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| − | ===Canine Disease===
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| − |
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| − | * Until 1978 Parvovirus enteriris was totally unknown in dogs.
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| − | * First seen in dogs in Australia.
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| − | ** Apeared very similar but perhaps slightly worse than the disease seen in the cat.
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| − | ** A new and distinct disease, but the virus is very closely related to the feline virus.
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| − | *** Viral DNA is 98% homologous to the feline virus.
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| − | ** The canine virus does NOT cause disease in cats.
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| − | * '''Clinical'''
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| − | ** Causes enteritis in young dogs over 6 weeks old.
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| − | ** Causes myocarditis in puppies.
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| − | ** Mainly affects the [[Small Intestine - Anatomy & Physiology|small intestine]].
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| − | * Vaccines are very effective, but the virus is hardy and survives in the environment.
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| − | * Diagnosis:
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| − | ** Look for viral antigen in the faeces by the red cell agglutination test.
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| − | ** Immunoflurescence.
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| − | ** ELISA.
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| − | ** Serology.
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| − |
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| − | ==Bacterial septicaemia and enteritis==
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| − |
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| − | * Some severe acute septicaemias cause very severe acute haemorrhagic enteritis with bleeding into the [[Alimentary - Anatomy & Physiology|alimentary tract]].
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| − | * Death is usually rapid.
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| − | * Fairly easy to diagnose
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| − | ** [[Small Intestine - Anatomy & Physiology|small intestine]] is full of dark, tarry, partly clotted blood (like black currant jelly).
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| − | * Associated with severe systemic disease, e.g.
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| − | ** '''Anthrax''' in cattle ([[Bacillus anthracis|''Bacillus anthracis'']]).
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| − | ** '''Leptospirosis''' in dogs.
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| − | *** Especially [[Leptospira|''L. icterohaemorrhagiae'']].
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| − | * Do not confuse with [[Warfarin Poisoning|warfarin poisoning]].
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| − | ** Also gives blood in [[Forestomach - Anatomy & Physiology|stomach]] and intestine BUT there are no signs of inflammatory disease.
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| − |
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| − | ===Lamb Dysentery (Enterotoxaemia with Blood)===
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| − |
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| − | * [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] causes very severe acute haemorrhagic enteritis.
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| − | ** Usually affects young farm animals
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| − | *** May also be seen in pets.
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| − | * Type B [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] infection of lambs leads to '''lamb dysentery'''.
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| − |
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| − | ====Clinical====
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| − |
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| − | * Lamb dysentery is usually seen in lambs under 2 weeks of age.
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| − | ** Related to being kept in a cold, dirty environment, with build-up of infection during the lambing season.
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| − | * Lambs may produce bloodstained [[Intestine Diarrhoea - Pathology|diarrhoea]] before death, but they often die before this effect is apparent.
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| − | * Diagnosed by culturing contents of gut.
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| − |
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| − | ====Pathology====
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| − |
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| − | =====Gross=====
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| − |
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| − | * The gut is blown and distended with foamy ,bloody contents.
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| − | * Sometimes ulceration with perforation and fibrinousperitonitis is seen.
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| − | * Focal or diffuse congestion and haemorrhages.
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| − |
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| − | =====Histological=====
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| − |
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| − | *Coagulative necrosis of villi.
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| − | * Oedema.
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| − | * Haemorrhage.
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| − | * Influx of inflammatory cells in the lamina propria and submucosa.
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| − |
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| − |
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| − | ====Similar Conditions====
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| − |
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| − | * '''Piglets''' show similar disease caused by [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] type C (and sometimes type B)
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| − | ** May look similar to a volvulus but with no twist present.
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| − | * In '''adult sheep''' [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']] type B infection causes '''Struck'''.
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| − | ** Enterotoxigenic gastritis.
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| − | ** Acute sudden death with haemorrhagic enteritis
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| − | ** Haemorrhagic enteritis is not as severe as in lambs, and tends to be more patchy.
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| − |
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| − | ===Colitis X===
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| | | | |
| − | * Affects the horse.
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| − | * Sudden onset with haemorrhages throughout body (shock) and sometimes acute foul smelling diarhoea.
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| − | * [[Colon - Anatomy & Physiology|colon]] is acutely haemorhagic and oedematous with mucosal necrosis.
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| − | * Associated with [[:Category:Enteropathogenic and Enterotoxaemic Clostridia|''Clostridium perfringens'']].
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| − | * Possibly an enterotoxaemia.
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| | [[Category:Intestine_-_Inflammatory_Pathology_by_Type]] | | [[Category:Intestine_-_Inflammatory_Pathology_by_Type]] |