NSW Farmers is seeking urgent action from the NSW Government to support farmers and rural communities in combating an escalating mice plague.

According to NSW Farmers Federation president James Jackson farmers in the Weddin Shire and many parts of regional NSW are reporting a drastic increase in mice populations, which have already begun decimating crops, destroying stored hay, grain and livestock feed as well as invading silos, sheds and homes.

Just as devastating and important for local farmers is the mice plague is also having a human health impact, with the NSW Western Area Health Service reporting increased cases of leptospirosis as a result of mice in domestic dwellings.

Leptospirosis is a disease spread from animals to humans, caused by infection with the bacteria Leptospira.

The most common sources of infection are contact with infected animal urine and/or contaminated soil or water.

Outbreaks may occur following periods of heavy rain or flooding.

Symptoms for leptospirosis include:

Mr Jackson said grain growers hold grave concerns about the winter crop planting season, which is due to commence in coming weeks.

"Farmers need some more control options," Mr Jackson said.

"We are requesting that an Emergency Use Permit be issued for Zinc Phosphide to treat seed.

"This will allow farmers to have their own grain professionally treated, removing the biosecurity risks posed by using foreign seed."

According to Mr Jackson it will also reduce the cost of sourcing sterilised or de-vitalised grain by farmers using their own treated seed to be sown for winter cropping.

Mr Jackson said NSW Farmers are also seeking some financial assistance through a small grants program.

"Mouse control is very costly," Mr Jackson said.

"The severity of the current plague has resulted in the need for multiple aerial and ground bait applications in cropping regions.

"Potential options we are putting up include a rebate on rodenticide products or a subsidy for ground and aerial baiting.

"Action is needed now."

Mr Jackson believes the mouse situation is only getting worse.

"Mice damage reports coming in from farmers and rural communities from the north, south and central west are increasing significantly," he said.