Following the deaths of at least six horses in the northern suburbs of WA due to suspected outbreak of the infection horse disease - strangles - the stables there were forced to be in a lockdown mode.

Strangles disease is a horse disease triggered by Streptococcus equi, a bacterium that invades nasal and throat passages and creates abscesses in lymph nodes.

Across the Wanneroo area, there are 30 suspected cases reported with deaths occurring around Yanchep.

Following the news of spread of the infection is probable due to the deaths of horses, horse and pony club events were cancelled yesterday.

In an effort to reduce contact between horses, Equestrian WA governing body released a biosecurity warning to restrict their movements.

The infectious horse disease is easily spread to other horses through ingestion and inhalation, the same water and food source, and other horse-related equipments.

The test to confirm the strangles outbreak will be done today by the Department of Agriculture.

The last warning from the department in 2005 required horses with the disease to be isolated as they are infectious for 4 or more weeks - significantly up to eight months in recovered horses - and beddings must be burnt, and stables and equipment to be thoroughly disinfected to prevent the disease spread.

According to Joe Byrne, Ascot horse trainer, in foals the disease usually is lethal and that owners must report the cases of infected stables.

He said the most damaging thing with strangles is the attitude of ignorance and secrecy.

Owners with infected stables straight away clam up, don't tell anyone and remain operating like nothing has happened, said Mr Byrne and that is very problematic.