More than 20 dogs have died and about 60 others have fallen ill after eating pet food contaminated with Indospicine.
The meat came from Maffra District Knackery, east of Melbourne, which slaughtered a truckload of horses from the territory in May.
The NT’s Department of Industry, Tourism and Trade has since traced the horses to a central Australian property after Victoria’s chief veterinary officer asked it to investigate.
The NT’s principal veterinary officer Peter Saville said the property owner sold 26 free-roaming, semi-domesticated horses in May.
“The property owner advised he was unaware the horses would be used to manufacture pet food,” he said.
The property manager was told the horses would be trucked to Queensland abattoir and be used for human consumption.
It’s understood the horses were re-directed south due to COVID lockdowns.
They ended up at the knackery in Victoria, which sold the contaminated meat to dog owners in Bairnsdale, Traralgon, Mornington Peninsula and Melbourne’s eastern suburbs between May 31 and July 3.
It’s since issued a voluntary recall of raw chopped pet meat.
Dogs are especially sensitive to Indospicine, but it’s the first time illness or death from the toxin has been reported in Victoria.
High levels of the toxin are found in native plants of the Indigofera species across northern Australia, where dogs fed contaminated horse or camel meat have previously been affected.
The plant is a low, spreading plant with a thick taproot that enables it to withstand drought conditions and respond rapidly to rainfall.
Horses that eat Indigofera can develop a permanent toxic condition known as Birdsville disease.
Affected horses show a variety of signs, including general weakness, a lack of coordination, shivering, twitching and swaying.
NT investigators didn’t find Indigofera at the property that sold the horses and the owner said none of the horses were suffering from Birdsville disease.
But Dr Saville said it could have been growing in patches across the 1000-square-kilometre property and been missed.
Samples from about 80 other horses on the property had been sent to a laboratory for Indospicine analysis.
The results will be provided to the Victorian authorities.
Victoria’s meat safety watchdog, PrimeSafe, continues to urge dog owners to check the source of their pet meat amid concerns some of the toxic meat could still be on sale.
It’s illegal in the NT to slaughter a horse for pet food if it’s suspected the animal has been in an area where Birdsville disease occurs.
The growing population of free-roaming semi-feral horses is a problem in the NT due to land degradation and animal welfare issues during dry times.
Few NT horses are sold for consumption due to the risk posed by Indospicine.
Dr Saville declined to identify the property that sold the horses.