Authorities are working to stop the spread of footrot in far-west New South Wales, after confirming one case in the region.
Western Local Land Services (LLS) declined to specify the affected area, but said it was working with the producer involved to limit the impact.
It said the affected area was in the southern part of the far west.
Western LLS vet Charlotte Cavanagh said landholders in the region must be on the lookout for symptoms in their stock.
"Benign or virulent footrot starts as an inflammation between the claws of the feet," Ms Cavanagh said.
"It can then progress quite quickly, and in virulent footrot, under the right environmental conditions, it can progress within a couple of weeks to severe underrunning of the hoof.
"So you'd obviously expect to see lame sheep."
The organisation said it had been more than 10 years since the far west last saw a case of footrot.
The disease is most common in warmer environmental conditions with a high level of moisture in or on the ground.
Ms Cavanagh said producers should take extra precautions to protect their animals.
"Individuals need to make sure that their boundary fences are secure, and that you're not having mixing of sheep between neighbours," she said.
"Producers must ask for relevant sheep or goat health declarations before they introduce any sheep or goats onto their properties.
"The National Sheep Health Declaration and the National Goat Health Declaration aren't compulsory in NSW, but producers need to ask for it."
Western LLS said anyone feeling emotionally impacted by the potential for footrot should contact Lifeline on 13 11 14.
