Definition of visna in English:

visna

noun

Veterinary
  • A fatal disease of sheep in which there is progressive demyelination of neurons in the brain and spinal cord, caused by a virus.

    • ‘It is a voluntary scheme with over 2800 flocks that have been blood tested and are accredited free of Maedi visna.’
    • ‘We conclude that sheep sera have a visna virus inhibiting factor and hypothesise that VIF inhibits early spread of visna virus in inoculated sheep and may be involved in initiating the persistent infection.’

Origin

1950s: from Old Norse, to wither.

Pronunciation:

visna

/ˈvisnə/