From Dept of Agriculture Victoria
Tuesday, 3 January 2023

Protect pigs and horses from mozzies this summer

Horse and pig owners are urged to protect their animals from mosquito-borne illnesses this summer after recent heavy rain and flooding.

Victoria’s Chief Veterinary Officer Dr Graeme Cooke said bite prevention and mosquito control were the key to keeping animals free from mosquito-borne diseases including Japanese encephalitis (JE), Ross River fever, Murray Valley encephalitis and West Nile virus (Kunjin strain).

“It is reasonable to anticipate that JE 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 Japanese encephalitis 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.

Japanese encephalitis virus 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.

Hendra virus infection must always be ruled out in cases of neurological disease in horses. Hendra and West Nile virus clinical disease can have human health implications so it is important to report suspect cases and get an accurate diagnosis to ensure the appropriate response.
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 JE, 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 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 the JE in pigs and horses visit .

For more information about Japanese encephalitis virus and human health contact your GP or phone NURSE-ON-CALL on 1300 606 024, or visit the Better Health channel .