|
|
| (4 intermediate revisions by the same user not shown) |
| Line 1: |
Line 1: |
| − | ====Paralytic Ileus==== | + | {{frontpage |
| | + | |pagetitle =Intestine - Functional Obstruction |
| | + | |pagebody = |
| | + | |contenttitle =Content |
| | + | |contentbody =<big><b> |
| | | | |
| − | * A common condition.
| + | <categorytree mode=pages>Intestine - Functional Obstruction</categorytree> |
| − | * Occurs following trauma or abdominal surgery.
| |
| − | * Stasis of gut flow due to failure of [http://en.wikipedia.org/wiki/Peristalsis| peristalsis].
| |
| − | ** Leads to distension with gas and fluid, as well as a flaccid intestinal wall.
| |
| | | | |
| − | =====Causes===== | + | </b></big> |
| | + | |logo =path-logo.png |
| | + | }} |
| | | | |
| − | * Anything which stops peristalsis, e.g.
| |
| − | ** Damage to nerve supply to intestine (autonomic nervous system)
| |
| − | ** Pain
| |
| − | ** Abnormal metabolism
| |
| − | ** Toxaemia
| |
| − | ** Electrolyte imbalance such as hypocalcaemia, hypomagnesaemia, and hypokalaemia.
| |
| − | * Also in
| |
| − | ** Diabetes mellitus
| |
| − | ** Uraemia
| |
| − | ** Tetanus
| |
| − | ** Lead poisoning.
| |
| | | | |
| − | =====Pathology=====
| |
| | | | |
| − | * loss of smooth muscle tone leads to a flaccid bowel.
| |
| − | * Bowel is distended with fluid.
| |
| | | | |
| − | =====Pathogenesis=====
| + | [[Category:Obstruction,_Intestinal]] |
| − |
| |
| − | * Intestine susceptible to neurogenic damage during an operation.
| |
| − | * Peristalsis fades away over a few days producing paralytic (adynamic) ileus.
| |
| − | * Particularly occurs if bowel handled roughly, or if serosa gets cold and dry at surgery.
| |
| − | * Very difficult to start peristalsis again but will sometimes respond to pharmacological or electrical stimulation.
| |
| − | * The horse is very susceptible, and the dog is somewhat suscpeitble.
| |
| − | | |
| − | ====Dysautonomia====
| |
| − | | |
| − | * Most notably affects horses and cats.
| |
| − | | |
| − | =====Equine dysautonomia, or grass sickness=====
| |
| − | | |
| − | * Most prevalent in the UK and western Europe.
| |
| − | ** Common in wetter areas, e.g. the South West.
| |
| − | * Seen in horses out at pasture in late summer and autumn.
| |
| − | * Usually affects young adults.
| |
| − | ** 6-7 years old.
| |
| − | * '''Clinical'''
| |
| − | ** Acute oneset:
| |
| − | *** Muscular tremors
| |
| − | *** Abdominal pain
| |
| − | *** Does not eat
| |
| − | *** Constipation
| |
| − | *** Become severly tympanic in acute cases
| |
| − | *** Dull and restless
| |
| − | *** Avoid swallowing
| |
| − | *** Salivate excessively
| |
| − | ** Degenerative lesions are seen in the autonomic nerve ganglia, including enteric plexuses
| |
| − | ** May either:
| |
| − | *** Progress rapidly to death
| |
| − | *** Take a slower clinical course.
| |
| − | **** Eat a bit, but food drops out of mouth
| |
| − | **** Go on to die slowly.
| |
| − | ** Some horses recover
| |
| − | *** This is very unlikely, and the condition is usually fatal.
| |
| − | ** Clinically difficult to diagnose - signs are confined to the gut.
| |
| − | *** Easy to diagnose on post mortem
| |
| − | * '''Pathology'''
| |
| − | ** [[Forestomach - Anatomy & Physiology|Stomach]] and [[Small Intestine - Anatomy & Physiology|small intestine]] large amounts of contain watery yellow fluid.
| |
| − | *** There is an abrupt change in the [[Large Intestine - Anatomy & Physiology|large intestine]], where no fluid is present.
| |
| − | **** [[Large Intestine - Anatomy & Physiology|large intestine]] has very dry mucoid contents.
| |
| − | * '''Pathogenesis'''
| |
| − | ** Due to functional obstruction at ileocaecal valve and a degree of paralytic ileus of the [[Small Intestine - Anatomy & Physiology|small intestine]].
| |
| − | ** The exact cause is unknown, but a type of bacterial or fungal toxin which may damage autonomic nervous system ganglia may be involved.
| |
| − | *** ''[[Clostridium botulinum]]'' is thought to be involved.
| |
| − | * A similar condition seen in hares
| |
| − | ** Certain yeares almost seem to have outbreaks.
| |
| − | * Certain pastures at certain times of year produce grass sickness quite often.
| |
| − | ** A definitive diagnosis must be made - if the condition is due to the grazing we need to know.
| |
| − | *** E.g. if on livery or stud grazing, may put people off going there.
| |
| − | * 'Diagnosis'''
| |
| − | ** At post mortem look for degenerative changes in coeliaco-mesenteric ganglia - need to examine histologically.
| |
| − | *** Ganglia are peanut sized and found in perirenal fat between adrenal gland and the aorta.
| |
| − | | |
| − | =====Feline dysautonomia, or Key-Gaskell Syndrome=====
| |
| − | [[Image:Ba 250 07.jpg|thumb|right|Histological section of degenerate neuron in feline dysautonomia(Courtesy of Susan Rhind)]]
| |
| − | * Occurs mostly in the UK and continental Europe.
| |
| − | * Is also of unknown aetiology. Suggested causative factors include:
| |
| − | ** Environmental toxins
| |
| − | ** Infectious agents
| |
| − | ** Botulinum toxins .
| |
| − | * Clinical signs:
| |
| − | ** Anorexia
| |
| − | ** Depression
| |
| − | ** Bradycardia
| |
| − | ** Decreased lacrimation,
| |
| − | ** Altered pupillary dilataion,
| |
| − | ** [[Megaoesophagus]]
| |
| − | ** Constipation.
| |
| − | * Degenerative lesions of autonomic nerve ganglia can be seen.
| |
| − | * Also occurs in the [[Key-Gaskell Syndrome|oesophagus]].[[Category:Obstruction,_Intestinal]]
| |
