WA Livestock Disease Outlook - for producers

Neurological signs (sudden blindness) in Simmental bulls

  • Cases of sudden-onset blindness were investigated in three one-year-old bulls in the South West.
  • One bull died but two responded to treatments of thiamine and vitamin A.
  • A range of tissue samples from the dead animal were submitted for laboratory testing.
  • Microscopic examination of the brain showed severe polioencephalomalacia, most commonly caused by thiamine (vitamin B1) deficiency.
  • Read more on thiamine deficiency induced polioencephomalacia (PEM) of cattle and sheep.