The first cases of deadly African horse sickness have been confirmed in Malaysia, with five animals affected.
The cases follow the first-ever outbreak of the disease in nearby Thailand, first reported in February, which reports have linked to the importation of zebras from Africa.
The disease is endemic in sub-Saharan Africa and is spread by biting midges.
Horses are considered the most susceptible, with nearly 90% dying if infected. It kills roughly half of infected mules and 10% of donkeys.
The report to the World Organisation of Animal Health (OIE) by the deputy director-general of veterinary services for Malaysia’s agriculture ministry, Dato’ Dr Norlizan Mohd Noor, put the start of his country’s outbreak at August 6. Confirmation that the disease was African horse sickness came three weeks later, on August 27.
The serotype involved — there are nine different forms of African horse sickness — has yet to be confirmed.
The outbreak is centered on a property in the state of Terengganu.
The source of the outbreak is currently listed as unknown or inconclusive, but serotyping the virus will provide clues as to whether there are any links with Thailand’s outbreak, which involves only serotype 1.
In his report, Dr Noor said the owner of the animals notified the Department of Veterinary Services’ state office that two of his five horses were limping, and that he suspected them to have soft soles.
“The owner also complained that his two limping horses were showing difficulty in breathing. However, during the visit, the difficulty in breathing was not observed by the veterinary officer.”
A week after the first visit (August 17), the owner reported to the department that a third horse now had a fever and was struggling to breathe.
The horse was treated with dexamethasone and benacillin.
Then, three days after the second visit, a fourth horse was reported limping, with a swollen hind leg.
Blood samples were taken from the four affected horses for testing, which revealed all were positive for African horse sickness.
A second sampling has confirmed five horses on the property are positive for the virus.
“Epidemiological investigation to determine the source of infection is ongoing,” Dr Noor said.
Malaysian authorities have imposed movement controls inside the country, surveillance, and quarantine measures in a bid to stop the spread of the disease. Horses will be screened and efforts to control the biting midges that can spread the disease are under way.
Vaccination against the virus is prohibited in the country.
Malaysia shares a border with southern Thailand, and Terengganu is some 200km from that border. However, the centre of the Thailand outbreak is further afield, at least 1000km away.
Thailand, which has used vaccination as a key strategy to contain the disease, has not had a confirmed case since mid-June.