Livestock

Watch out for blue-green algae, says Agriculture Victoria

By Rodney Woods

The current seasonal conditions remain standard for blue-green algae to thrive in farm water supplies and Agriculture Victoria is warning livestock owners to remain alert.

Victoria’s acting chief veterinary officer Dr Cameron Bell said blue-green algae poisoning could result in poisoning of livestock, including pets.

“As there is no specific treatment for blue-green algae poisoning, producers should check farm water supplies daily for blooms, as this remains the most effective way of preventing stock deaths,” he said.

“Blue-green algal blooms typically appear as surface scum that looks like a suspension of green paint or curdled green milk, often with an earthy smell.

“However, the colour may range from pale green to dark brown.”

Deaths can occur when stock drink toxins produced by the blue-green algae, often when it is concentrated on the down-wind side of a water supply and has formed a dense, surface scum.

Animals that have consumed blue-green algal toxin may appear ill very rapidly, develop a staggery gait, collapse, begin to convulse and die — typically within 24 hours — depending on the toxicity of the bloom and the concentration of the toxin.

Those that do not die immediately often suffer severe liver damage.

This may lead to the development of jaundice (‘the yellows’) or photosensitisation over the next few days.

Dr Bell said animals that recovered from these ailments often suffered from chronic ill-thrift.

If a suspicious bloom is noticed, stock should be removed as quickly as possible, and a safe alternative water supply provided.

Further information on blue-green algal contamination in your irrigation water source or livestock water supply is available on the Agriculture Victoria website at: agriculture.vic.gov.au/agriculture/farm-management/blue-green-algae-issues