PIRSA is advising sheep producers, particularly those in high rainfall areas, to be vigilant on the health of pregnant ewes following reports of a number of late term abortions.
Chief Veterinary Officer, Mary Carr said early laboratory results indicate that the likely cause is a bacterial infection caused by Campbylobacter fetus spp (formerly known as ovine vibriosis).
"Ovine campylobacteriosis is one of the infectious causes of abortion in ewes which normally occurs during late preganancy," she said. "It is highly contagious and can spread quickly within a flock.
"Campylobacter abortions occur mainly during cold, wet seasons and can be associated with intensive management practices where ewes are congregated close together.
"The infection enters a property in the intestines of seemingly healthy animals. It can also be introduced by carrion spread by wild animals and in the droppings of birds and foxes even weeks after they have initially ingested the contaminated material."
Dr Carr said given the highly infectious nature of the disease, producers need to be aware that all aborted tissues, foetal membranes and discharges will be infectious and should be collected and removed as quickly as possible to prevent further spread of infection within the flock and to protect the water supply from contamination.
"Anyone handling aborted lambs, ewes with discharges or placental material should also practice strict hygiene measures including wearing gloves and to take care to disinfect hands and clothing afterwards.
"Affected ewes may be treated with antibiotics to try to reduce losses through uterine or generalised infection. There is a commercially available vaccine that may provide immunity against Campylobacter abortion and should be used prior to any potential exposure to the disease.
"Producers who believe their flock or some groups of their ewes may be at risk, should discuss vaccination and other options with their veterinarian.
"While most ewes can recover promptly from the disease and are immune afterwards, producers should be aware that some sheep may continue to carry the disease and remain a source of infection to other susceptible animals, particularly any ewes that have been newly introduced onto a property."
Dr Carr said it was also important to note that in addition to campylobacter there are a number of other infectious causes of abortions in ewes, such as salmonella and including Brucella melitensis a notifiable exotic disease.
"For this reason it is important that producers not make assumptions about the cause of the abortions, but to have them investigated by their veterinarian," she said.
"PIRSA does have funding available to support private veterinary investigations into the outbreak of livestock diseases, including abortions and producers should discuss taking up this option with their veterinarian."
For further information on PIRSA’s Livestock Disease Surveillance program visit www.pir.sa.gov.au/biosecurity/animal_health/veterinarians/livestock_disease_surveillance