ENTV is a virus that causes tumorous growths in the ethmoid bone of sheep, primarily reported in several European countries but not found in Australia, New Zealand, or the UK. The UK instead deals with jaagsickness, a similar condition caused by a related virus affecting sheep's lungs, endemic to the region. Both viruses share a long incubation period, posing significant concerns for sheep farmers due to their detrimental effects on animal health. A notable case of jaagsickness was identified in the Netherlands in 2021, marking the first occurrence since 1978, which prompted actions to curb its spread, with no subsequent cases reported.