International horse transport has been blamed for the first outbreak of equine influenza in Malaysia in nearly 40 years. The occurrence has resulted in a disruption of events in the racing industry and a complete ban on horse movement in and out of the country, according to official reports.

Horse races across the country have been cancelled since the outbreak was detected in late August. However, morning gallops were allowed to resume at affected courses last week.

As many as 400 horses might have been exposed to the disease at the Selangor Turf Club in Kuala Lumpur, said Mohamad Azmie Zakaria, DVM, PhD, director general and chief veterinary officer in the Department of Veterinary Services and Ministry of Agriculture and Agro-Based Industry in Putrajaya.

Of those horses, two were found to be positive for equine influenza in mid-August. Both horses had been imported, Zakaria reported in an official outbreak notification published by the World Animal Health Organization (OIE). According to the Malayan Racing Association (MRA) in Keri Kembangan, as many as 90 horses have fallen ill at Selangor. “Those treated with antibiotics are recovering well,” said Krishna Kumar K, secretary at the MRA.

While no other official reports have been made to the OIE to date, another Malaysian racecourse has also declared that its horses have been infected with equine influenza. The Perak Turf Club in Ipoh began canceling races in early September due to an “outbreak of respiratory disease” in its home stables, according to the club’s published cancellation notices. About 30 horses at this site have been isolated after showing signs of illness, according to the MRA.

At the Penang Turf Club, a single horse showed signs of the disease. The horse was isolated and treated with antibiotics. It has since recovered, the MRA reported.

Equine influenza has been nonexistent in Malaysia since 1977. The origin of the outbreak had been recorded as the “introduction of new live animals,” the OIE notification stated.

Affected horses have been treated with antibiotics and anti-inflammatory medications, and no deaths have been reported.

Veterinarians have sought to control the outbreak through disinfection of the affected areas, quarantine of infected horses, and a screening and traceability program of animals that could have been affected. Officials also set up a strict ban on international movement, allowing no horses to leave or enter the country until the disease has been completely eradicated. Eradication is determined by a period of 28 days from the last outbreak.

Vaccinations were not administered, the OIE said.