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| | ===[[Sodium and Water Excess]]=== | | ===[[Sodium and Water Excess]]=== |
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| | + | ===[[Sodium Excess]]=== |
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| | + | ==Abnormal States of Potassium, Magnesium and Calcium Balance== |
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| − | ===Sodium Excess=== | + | ===[[Hypomagnesaemia]]=== |
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| − | * Known as "salt poisoning".
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| − | * Occurs sporadically in the U.K. as a group or herd problem in intensive systems.
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| − | * Mainly affects pigs and poultry.
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| − | * Caused by:
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| − | ** Accidental ingestion of excess salt
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| − | *** Either by dietary contamination, or error.
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| − | ** Deprivation of water on relatively high salt diets.
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| − | *** This is the more likely scenario.
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| − | * Salt poisioning may be
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| − | ** Peracute/ acute
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| − | ** Subacute/ chronic
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| − | ====Peracute / acute==== | + | ===[[Hypokalaemia]]=== |
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| − | * Peracute cases are often found dead.
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| − | ** Only shock haemorrhages are seen at autopsy.
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| − | * Acute cases present as abdominal pain, diarrhoea and vomiting.
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| − | ** Death occurs in 24 - 48 hours.
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| − | ** At autosy, may see:
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| − | *** Shock haemorrhages.
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| − | *** Gut congestion.
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| − | *** Fluid accumulations in body cavities.
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| − | ====Subacute / chronic====
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| − | * These cases show nervous signs.
| + | ===Calcium=== |
| − | ** Convulsions
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| − | ** Blindness
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| − | ** Ataxia
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| − | * Show excessive salivation.
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| − | * May be polyuric.
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| − | * Fluid may accumulate subcutaneouslt and in the abdomen.
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| − | * Macroscopic findings are inconclusive.
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| − | | |
| − | ====Diagnosis==== | |
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| − | * For definitave diagnosis, histological examination is required. | + | * '''[[Hypocalcaemia]]''' is most significant. |
| − | * On histological examination, the following may be seen:
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| − | ** Perineuronal vasculation and cerebral neuronal necrosis.
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| − | *** '''Polio-encephalomalacia'''.
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| − | ** Eosinophilic meningoencephalitis.
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| − | ** Perivascular oedema in the brain.
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| − | ==Abnormal States of Potassium, Magnesium and Calcium Balance==
| + | * '''[[Hypercalcaemia]]''' is less common. |
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| − | ===Hypomagnesaemia===
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| − |
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| − | * Magnesium is important for muscular and nervous conduction. | |
| − | *Low Mg <sup>++</sup> diets may induce acute hypo-magnesaemia in lactating cows.
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| − | ** Seen as tremors and convulsions (tetany).
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| − | ** For example, poor quality silage.
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| − | * High K<sup>+</sup> diets induce a relative Mg<sup>++</sup> imbalance.
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| − | ** For example, lush pasture.
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| − | ** Known as "grass staggers".
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| − | ** Produces tetany and ataxia, and sometimes cardiac arrest.
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| − | ** Only shock haemorrhages can be seen at autopsy; i.e. non-specific findings.
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| − | | |
| − | ===Hypokalaemia===
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| − | | |
| − | * Potasstium is important for nervous and muscle conduction, especially in cardiac muscle.
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| − | * The hypokalaemia is associated with diarrhoea and dehydration in calves.
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| − | ** Animals die from cardiac arrest following ventricular dissociation.
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| − | | |
| − | ===Calcium===
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| − | * '''Hypocalcaemia''' is most significant.
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| − | ** "Milk fever" in lactating cattle.
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| − | ** Eclampsia (parturient tetany) in bitches.
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| − | * '''Hypercalcaemia''' is less common.
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| − | ** Usually the result of dietary imbalance.
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| − | ** Produces metastatic vascular calcification.
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| − | [[Category:Circulatory Disorders - Pathology]] | + | [[Category:Vascular Fluid|A]] |
| | + | [[Category:Cardiology Section]] |