Authorities in Western Australia working to identify a mystery horse ailment that may have affected people are stressing that the condition is not widespread.
The state’s Department of Agriculture and Food said it was continuing to test samples to identify the cause of mouth papules – small, solid rounded lumps – reported in horses on three properties in the southwest region.
The movement of horses and equipment have been identified as potential links between the affected properties, the department said.
“Extensive communication with private equine veterinarians has verified the condition is not widespread and is not causing any serious health signs in horses,” a spokesman said.
“There have also been reports that some humans who have had contact with affected horses have developed similar lesions in their mouths, although they remain generally well.
“The Department of Health has been assisting with the investigation of these cases. At this stage, it is not clear if there is a relationship between the lesions reported in horses and people, and testing has not revealed a cause for the lesions in either horses or people.”
The Department of Health advised those handling affected horses to take general precautions, such as wearing disposable gloves and a face mask, and washing their hands well after contact with affected horses.
The initial case in a horse was reported about four weeks ago by Pinjarra veterinarian Michael Gibbs and his staff while attending to a client’s horses.
Aside from Pinjarra, cases have also been reported in the Swan Valley.
The property was quarantined while initial testing was undertaken to rule out the main virus of concern, vesicular stomatitis. That disease was ruled out and the property was no longer under quarantine.
“While preliminary tests on eight of the 18 horses on the three properties indicated the lumps may be a response to a virus, this has not been confirmed,” the spokesman said. “Subsequent tests have all been normal.”
The department is continuing to work with the veterinary clinic involved to finalise a diagnosis.
The spokesman said affected horses had mild signs, which have now resolved on the initial property.
He said it was likely that people examining normal, healthy horses’ mouths may see small lumps and mechanical damage from hay and grass seeds that are not necessarily of concern.
“The department … reminds horse owners to contact their local veterinarian if they notice unusual signs in their horses.”
There are no restrictions on horse movements in Western Australia or on events. The department’s standard horse biosecurity recommendations are that only healthy horses should attend events and they should not share feed, water, or tack and equipment with other horses.