DESPITE no reported cases in Victoria since last summer, Victoria’s chief veterinary officer, Dr Graeme Cooke, has reminded horse owners and pig farmers to protect animals from mosquitoes, after recent, unseasonal heavy rain and flooding.

He said bite prevention and mosquito control were 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.

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.

Removing stagnant water or fixing dripping or leaking taps and water troughs, is critical in reducing breeding sites and risk of arbovirus.

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.

“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 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 agriculture.vic.gov.au/JE.

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