Earlier this year, as the world at large was transfixed upon the escalating COVID-19 pandemic, another exotic disease quietly popped up in northern Australia. This one affected dogs.
Ehrlichiosis, a tick-borne bacterial illness, was found in Australian dogs in Western Australia’s Kimberley region for the very first time in May.
At that point, animal health authorities were unsure where the disease—typically more common in tropical and subtropical regions—had come from. Now they believe the outbreak may have been the result of pet dogs not being tested properly before being imported into the country.
"It must have come in on a dog that was imported into Australia," Australia's chief veterinary officer, Dr Mark Schipp, told the ABC. "The testing is not 100 percent reliable and we know we've had situations where dogs have tested negative, and after being imported they've been found to be infected."
If that’s true, it raises serious concerns around the safety of current international testing standards and the possibility of the life-threatening disease spreading through Australia as a result.
"We haven't detected what the original source is … [but] any dog that entered Australia which is infected and has been bitten by a tick could be a source of the outbreak,” said Department of Primary Industries Chief veterinary officer Michelle Rodan. "Once it's in the tick population, it's very difficult to control. So the first stage is defining how widespread the distribution is and then in the interim trying to contain it to a region."
Signs of infection in dogs typically include flu-like symptoms such as fever, lethargy, loss of appetite, weight loss and bleeding disorders. Dr Rodan noted that while containment measures were in place to help prevent the spread of the disease interstate, the high population of wild dogs in the region posed an issue.
“There has been some surveillance last year and in previous years that would lead us to think it's not being detected in the wild dog population,” she said, “[but] wild dogs may become a source of infection if it continues to spread.”
While it cannot be directly passed from one dog to another, infected ticks can easily transmit the disease and spread it throughout populations—in some cases even giving it to humans. Symptoms of the illness in people range from mild body aches to severe fever, and usually appear within a week or two of a tick bite.
Imported pet dogs are not required to be tested for ehrlichiosis in Australia, provided they have been cleared by testing in their country of origin. But a spokesperson for the Department of Agriculture told the ABC that there was no international standard for those tests—and despite the recent detection of the outbreak, Australia’s import conditions haven’t changed.
A review of those conditions may be enacted, pending the results of an investigation into the current outbreak.