As NSW wades through another spell of relentless rain and thunderstorms, sheep are being exposed to increased internal parasites and flystrike.
And growth rates are expected to be impacted as the wetter, cooler conditions threaten to continue.
According to numerous Local Land Services, cases of mosquito, worms and flies are already troubling flocks as well as an increase in lameness.
Central west LLS mixed farming officer Matt Jones said it was a tough time for all producers experiencing flock issues.
"Talking with sheep producers around Nyngan, Trangie and Warren, they are fighting a number of challenges at once," Mr Jones said.
"The wet conditions are directly causing feet issues with sheep either walking through water or mud, which is not allowing the feet to dry out and creating lameness.
"Large bodies of water and an abundance of green grass has created the perfect conditions for mosquito populations to explode."
North west LLS district veterinarian Dr Shaun Slattery said many north west sheep flocks were impacted by flystrike and Barber's Pole Worm.
"Delays in shearing and crutching, chemical resistance and the need to avoid chemicals that will further delay shearing due to long wool harvest Intervals are all challenging for fly strike management," Dr Slattery said.
"Wet and mild weather, mobs flood-isolated in small areas and in some cases drench resistance, is also contributing to barber's pole deaths."
Flocks that have already seen barber's pole cases are most at-risk as they now have heavy pasture larval contamination, Dr Slattery said.
"These will need increased management and drenching to prevent further deaths," he said.
According to south east LLS regional agricultural landcare facilitator Marien Stark, livestock growth rates would likely be suppressed by the ongoing wet, cooler conditions.
And she said wool quality is likely to be compromised due to the excessive wet conditions.
"In the tablelands region of the south east, due to the excessive wet conditions, sheep more likely to experience fleece rot/green wool," Ms Stark said.
In the Riverina, LLS district veterinarian Dr Dione Howard said their team had been working with landholders to diagnose lameness issues, discuss flystrike and worm prevention strategies and reduce the risk of metabolic disease associated with severe weather events.
"If producers have lame sheep the cause of lameness should be diagnosed to make sure the most effective treatment is used," Dr Howard said.