Sodium Excess

• Known as "salt poisoning".
• Occurs sporadically in the U.K. as a group or herd problem in intensive systems.
• Mainly affects pigs and poultry.
• Caused by:
  • Accidental ingestion of excess salt
    • Either by dietary contamination, or error.
  • Deprivation of water on relatively high salt diets.
    • This is the more likely scenario.
• Salt poisioning may be
  • Peracute/ acute
  • Subacute/ chronic

Peracute / acute

• Peracute cases are often found dead.
  • Only shock haemorrhages are seen at autopsy.
• Acute cases present as abdominal pain, diarrhoea and vomiting.
  • Death occurs in 24 - 48 hours.
  • At autosy, may see:
    • Shock haemorrhages.
    • Gut congestion.
    • Fluid accumulations in body cavities.

Subacute / chronic

• These cases show nervous signs.
  • Convulsions
  • Blindness
  • Ataxia
• Show excessive salivation.
• May be polyuric.
• Fluid may accumulate subcutaneouslt and in the abdomen.
• Macroscopic findings are inconclusive.

Diagnosis

• For definitave diagnosis, histological examination is required.
• On histological examination, the following may be seen:
  • Perineuronal vasculation and cerebral neuronal necrosis.
    • Polio-encephalomalacia.
  • Eosinophilic meningoencephalitis.
  • Perivascular oedema in the brain.