Three Day Sickness, also known as Bovine Ephemeral Fever (BEF), is a viral disease of cattle transmitted by mosquitos and midges.

"In our region, it normally arrives in mid to late summer," HLLS District Vet, Dr Lyndell Stone said. "However, the dry weather seems to have changed this normal pattern and we are yet to have any convincing evidence of BEF cases this year.

"This is on the back of very minimal distribution of three day sickness last year."

If cattle are young when first infected, they develop strong long-term immunity against further infection.

"If our region misses distribution of the virus again this year it means our stock will be a bit older, heavier, pregnant and/or lactating when it does arrive in a future summer with strong mosquito and virus transmissions," Dr Stone said.

"In this situation, the impact of the virus on older animals can be more severe.

"When this has occurred in the past, producers worry that they are seeing a more severe variant of the fever, however they needn't worry as the virus is actually very stable and hasn't changed over the years."

The District Vet team is advising if we miss another summer of BEF distribution, producers may need to consider vaccinating their older and/or higher value stock towards the end of this year against a 2020 BEF season.

As of mid-May, BEF is circulating around the Kempsey area but hasn't progressed further south as yet.

Animals affected by BEF experience a sudden onset of fever over 40 degrees, become stiff in their joints, lame and are often reluctant to move. They may drool, have watery eyes and a nasal discharge.

"Infected animals will often go down, heavy animals, such as bulls and pregnant cows, appear to be affected the worst,' Dr Stone said.

"Cattle are typically only unwell for a few days, hence the name Three Day Sickness - however, a small proportion of cattle can take weeks to get up.

"Three Day Sickness can be diagnosed with a blood test, but only in the very early fever stage of the disease and on clinical signs."

As a service, District Vets track which diseases are circulating so that early warnings are given and producers are assisted to decide what vaccinations and preparations they need to consider, therefore reporting suspect cases to your local District Vet is appreciated.

Producers with questions regarding Three Day Sickness or to report suspect cases can contact a Hunter Local Land Services District Veterinarian on 1300 795 299 or their local vet.