Hunter Local Land Services has since received reports of at least three more suspected cases.
Kikuyu poisoning occurs sporadically in cattle, especially where rapid growth follows a protracted dry period like the region has recently experienced.
Kikuyu is a reasonably drought tolerant pasture, so after rainfall it grows rapidly and kikuyu poisoning most commonly occurs shortly after rainfall.
Cattle appear to be most commonly affected but sheep and goats are also susceptible.
Kikuyu pastures are a perennial, spring/summer/autumn growing grass that is a predominant pasture across much of the Hunter.
Hunter Local Land Services District Vet Digby Rayward said landholders need to take precautions now, after more rain fell in parts of the region at the start of March.
Producers need to regularly monitor stock on kikuyu dominant pastures and where possible provide alternate feed such as silage or hay.
“Generally cattle dislike and avoid the affected kikuyu pasture and poisoning only occurs when they have no other choice but to eat the toxic pasture,” Digby said.
“Over my 40 year career as District Vet I have seen less than 20 cases of kikuyu poisoning, with the most extreme case in the Tea Gardens area, where 70 cattle died.
“Kikuyu poisoning is an acute disease usually occurring 24-48 hours after exposure to toxic pasture which can result in sudden death.”
Other clinical signs that may be seen in cattle with kikuyu poisoning include drooling, sham drinking, tongue paralysis, dehydration, unusual vocalisation, abdominal pain, distended rumen, smelly green diarrhoea, lack of coordination, staggering, high stepping gait, aimless wandering, lying down and reluctant to move.
Diagnosis is based on clinical history, post mortem and laboratory testing.
“There is no specific treatment available for kikuyu poisoning but they can recover if removed from the toxic pasture and supportive care is provided,” said Digby.
“It is recommended to remove stock from the pasture for as long as possible, then slowly and carefully reintroduce them to the paddock.
“It is important to provide another feed source such as hay or silage to dilute out the toxin if any still remains.”
Also regularly check stock and monitor if they are avoiding any sections of a paddock.