Victoria’s chief veterinary officer Graeme Cooke said bite prevention and mosquito control were the key to keeping animals free from mosquito-borne diseases including Japanese encephalitis virus, Ross River fever, Murray Valley encephalitis and West Nile virus (Kunjin strain).
“It is reasonable to anticipate that JEV may again affect livestock in Victoria, however there have been no reported animal cases in Victoria since pig cases were seen last summer,” Dr Cooke said.
The most common signs of JEV in pigs are mummified and stillborn or weak piglets, some with neurological signs. Very young piglets may exhibit signs of central nervous system disease, however, the majority of pigs appear unaffected.
JEV is not spread directly from pigs to people, and there is no risk to humans from eating pig meat.
Horses may show no signs of illness from arbovirus infections, but these diseases can present with fever, loss of appetite, jaundice, lethargy, neurological or musculoskeletal signs such as staggering, incoordination, weakness and depression.
Dr Cooke said Hendra virus infection must always be ruled out in cases of neurological disease in horses.
Hendra and West Nile virus clinical disease could have human health implications so it was important to report suspect cases and get an accurate diagnosis to ensure the appropriate response, he said.
Horse owners can protect their animals by rugging and hooding them to prevent bites and stabling them between dusk and dawn, as the mosquito most likely to carry diseases of concern is a night-time feeder that stays outdoors.
Reducing mosquito breeding sites by removing stagnant water or fixing dripping or leaking taps and water troughs is critical in reducing the risks of arbovirus.
“Where it’s not possible to fully eliminate breeding sites, people should treat them with an appropriately registered larvicide,” Dr Cooke said.
Animal owners suspecting JEV, Hendra and West Nile virus clinical disease should notify their vet or the Agriculture Victoria Animal Health and Welfare team, the Emergency Animal Disease Watch Hotline on 1800 675 888 or the Notify Now App.
People with increased exposure to mosquitoes may be at a higher risk of infection, particularly people working or living on or near pig farms.
For information about JEV in pigs and horses, visit: agriculture.vic.gov.au/JE