A vet from one of the UK's largest dedicated equine practices is hopeful the outbreak of equine flu can be effectively controlled.

The British Horseracing Authority called off all race meetings today, after the Animal Health Trust confirmed three positive tests from vaccinated horses in Donald McCain’s yard in Malpas, Cheshire.

Oliver Pynn from Rossdales said: "The flu virus changes all the time and this is a strain we haven't seen for a while. The vaccine will offer some protection so what we are advising our clients to do, in accordance with BHA advice, would be that everything has a six-monthly booster for influenza.

"We take sensible bio-security measures, we take temperatures, we're looking out for clinical signs, we try to keep groups of horses together and not mix up different groups and we're being sensible about moving horses.

"It is spread through an aerosol, like coughing horses, the same as human flu, so you need to make sure everyone is taking sensible precautions, which you should do around horses anyway.

"The whole horse population is obviously affected, but while we need to be aware of it and take sensible precautions, hopefully it can be kept under control.

"There have been several other cases in recent weeks away from racing, but hopefully people vaccinate sensibly, take good bio-security measures and investigate the cases until we get an idea of how far and wide this has spread.

"There's a lot of testing going on at the moment and then we can get a feel of where the virus is and how we can manage it.

"In a vaccinated population, the symptoms that show aren't too severe, but in young stock not vaccinated - particularly new-born foals, of which there are plenty at the moment - it can be quite serious."

Professor Christopher Proudman, head of the School of Veterinary Medicine at the University of Surrey, believes the decision to call a temporary halt to racing should minimise the impact of the illness.

He said: "The early, decisive action taken by the British Horseracing Authority will minimise the risk of transmission of the virus between racehorses, thereby minimising the impact of this serious threat to horse welfare."

Equine influenza symptoms include high fever, coughing and nasal discharge.

Trainer Donald McCain said the origin of the infection is unclear.

He said: "I have been aware of the recent news about equine influenza outbreaks in France and Ireland, and over the last couple of days, I have been concerned about the health status of a small number of horses in the yard.

"Their welfare is at the front of our minds, so at my request, our veterinary surgeon has examined them regularly and we have followed his advice on testing and treatment.

"It was by following this protocol that the positive results for equine flu came to light.

"The BHA were contacted immediately and we are liaising closely with them about bio-security and management of all the horses at Bankhouse.

"Bankhouse follows all the available advice on disease control and all our horses are fully inoculated.

"We are scrupulous about observing the health status of horses in our care and taking the necessary steps to treat any condition that may affect them.

"It follows we would never race any horses that we could have known were infected.

"Over the last two months, all potential runners have been scoped and their blood checked within 36 hours of their races to ensure that only healthy horses compete for the yard.

"When new horses arrive at our yard we, as much as possible, try to keep them separate but at this stage cannot know if the infection came from recent arrivals or from horses returning from racing.

"We have three confirmed cases and have taken blood and swabs from all the others for testing."

David Sykes, director of equine health and welfare at the BHA, added: "We would like to thank Donald McCain for his co-operation in this matter, and for the responsible manner in which he has dealt with this issue, under the guidance of his veterinary surgeon. He has acted professionally with the interests of the racing industry and the health of his horses as his priority."