[citation needed] ARGT is a neurological condition and affects the brain.
Sheep may at first appear perfectly normal, but if driven for a hundred metres or so, the slight stress will cause mildly affected animals to lag behind the rest of the flock and exhibit a high-stepping gait.
More seriously affected animals may lose co-ordination and stumble, but will usually recover and join the rest of the flock if left quietly alone.
[2] Herbicide applications aimed to reduce ryegrass population have been successful in reducing the risk of ARGT but have undesirable effects such as rapid reduction in pasture productivity and increase in ryegrass herbicide resistance.
[citation needed] A recently released biological control agent, the twist fungus, has been demonstrated to be effective in reducing the risk ARGT without the need of controlling ryegrass.