Significant fly issues have already been noted in some regions, and the timing and level of future high concentrations of flys may vary across the state.
Agriculture Victoria Senior Veterinary Officer Robert Suter said regular inspections of all mobs is vital.
“In Victoria, scouring and dags are the major risk factors for breech strike and there have been a large number of reports of dirty sheep this spring,” Dr Suter said.
“Simple management tools to help prevent breech strike include controlling worm burdens by monitoring faecal egg counts and drenching as needed.”
“Crutching and timely shearing can also significantly reduce the likelihood of strike, ideally crutching prior to flies becoming a problem.”
Body strike is most likely to occur when sheep have fleece rot or dermatitis (also called lumpy wool or dermo).
Belly strike is more likely to occur in sheep with footrot. Infected sheep frequently have moist and smelly feet. When the sheep lie down, moisture from the feet touches the wool making it wet and odorous, consequently attracting flies which can result in belly or body strike.
Dr Suter said fly strike prevention is always better than a cure.
“In addition to standard management tools, preventative chemical treatment may be considered to help protect sheep from fly strike.”
“Application of preventative chemicals can provide protection throughout the spring and reduce fly pressure into summer. Chemicals should always be strictly applied in line with label directions.
“Wool and meat withholding periods must also be adhered to and should be carefully considered to ensure they don’t restrict future management options.”