Owners are advised to request Fodder Vendor Declarations when buying hay containing substantial quantities of ryegrass and to have hay from their own properties tested for ARGT. This follows recent horse fatalities linked to the consumption of toxic hay.
Department veterinary officer Marion Seymour said ARGT was a serious and usually fatal disease that occurred when livestock ate annual ryegrass seed heads infected with a toxin-producing bacterium.
“Annual ryegrass is present in much of the oaten and meadow hay grown and sold commercially for animal consumption in Western Australia,” Dr Seymour said.
“Although ARGT occurs mainly in spring when stock graze pasture containing infected ryegrass seedheads, outbreaks can occur any time of the year from feeding hay containing the toxic seedheads.”
Dr Seymour said the toxin was cumulative and signs did not appear until a near-fatal dose was ingested.
“The time taken for clinical signs to appear depends on the amount of hay or pasture being consumed and the amount of toxin present in the seedheads,” she said.
“Signs include weakness, loss of coordination, staggering, convulsions and eventual death. Occasionally animals may die before signs are noticed.
“The department strongly recommends that all stock owners and feed store merchants ensure hay containing annual ryegrass is tested for the presence of the bacterium that causes ARGT. The bacterium cannot be detected by visual inspection.
“When buying hay, ask for a Fodder Vendor Declaration available from the Australian Fodder Industry Association website at www.afia.org.au. The vendor declaration gives details of the hay quality and any testing.
“For hay already on the property or to test for the presence of ARGT in your pastures, contact your local department office for annual ryegrass and hay sampling and submission kits and request the quantitative ARGT test.
“Landholders should also be aware that bringing infected hay onto their properties may infect their own pastures.”
For more information, contact your local Department of Agriculture and Food office, the Department’s Animal Health Laboratories in South Perth on (08) 9368 3351, the Small Landholder Information Service on (08) 9733 7777 or visit the department website at www.agric.wa.gov.au and search for ‘ARGT’.