The NSW Livestock Health and Pest Authority is alerting producers to be on the lookout for signs of three-day sickness after the disease was recently confirmed in cattle in the St Albans and North Richmond areas in the north west of the Sydney Basin.
Cases were also seen in beef cattle at the Sydney Royal Easter Show in late March. Laboratory testing has confirmed the disease on a property at Berry (Illawarra Coast) last week, representing a major extension in the distribution of the disease.
Cumberland LHPA Senior District Veterinarian Keith Hart said that the current outbreak has been expected.
“Veterinary colleagues in north coastal NSW have been reporting cases of three day sickness since December last year. There was a confirmation at Maitland in late February, and cases were reported in the Mangrove Mountain and Wyong area in the last two weeks, so it was only a matter of time before the disease spilled over into the Sydney Basin,” he said.
Three day sickness is spread by biting insects, usually mosquitoes, and the number of current reports indicates that there are a large number of vector insects carrying the virus as a result of good rainfall during summer.
Dr Hart advises that cattle should be checked regularly for signs of the disease, which include lethargy, lameness and drooling. Three day sickness can also temporarily reduce fertility in bulls so it’s important that it be checked for and diagnosed as soon as possible.
“Sick animals should be provided with water and shade. If recumbent bulls are found or if you have other valuable animals that could be affected, consult your private veterinarian,” said Dr Hart.
“It’s far too late to attempt vaccination, but cattle owners could consider using one of the insect repellent pour-ons to give some protection to vulnerable classes of cattle such as bulls, pregnant cows and lactating dairy cattle.
“Insect transmission of three day sickness can be expected until early winter, so treatment may need to be repeated three to four weeks later”.
The Cumberland LHPA will be monitoring to see how far south the virus spreads on the Illawarra coast before winter. In the past, three day sickness spread has been confined to areas north of the Shoalhaven River.
“This year could be an exception, so cattle owners located south of the river should also be on the lookout for symptoms of three day sickness in their cattle”.