Ehrlichiosis, deadly dog disease spread by brown dog tick on the move

In just six months many hundreds of dogs have already died in Western Australia and the Northern Territory from the tick-borne disease canine ehrlichiosis.

Queensland has imposed border controls on dog movements but Professor Peter Irwin, principal of the College of Veterinary Medicine at Perth's Murdoch University, said it is unlikely Covid-style border restrictions can work.

Working dogs, wild dogs, domestic dogs can all fall victim to this highly infectious disease.

"This is a disaster which is happening right now, it has got in and there's no way to get it out again," Prof. Irwin said.

"It is not breed specific, the most vulnerable would be those dogs with no tick control, but even that is no guarantee."

The bacteria ehrlichia canis was first detected at Halls Creek and Kununurra in the WA back in May and was then found in Katherine NT in June.

Along with rabies, the ehrilichia bacteria was the main target for Australia's long established quarantine restrictions on overseas dog arrivals which won international attention during the then Agriculture Minister Barnaby Joyce and Hollywood actor Johnny Depp's dog fight back in 2015.

Veterinarian Bonny Cumming who works in remote communities throughout northern Australia with Animal Management in Rural and Remote Indigenous Communities said it was not sure how long the disease had been in Australia, likely months before it was first detected.

"It is a really horrible disease which can strike down the healthiest and youngest dogs," Dr Cumming said.

"Even those treated for ticks can get it with just one bite ... some seem to recover and then crash."

"Some seem to regard this as a tropical disease because of the ticks but it is not, no it is not, it is spreading fast and it is going to spread everywhere.

"I am not confident we can do anything about stopping it."

Ehrlichiosis is now a nationally notifiable disease and Queensland biosecurity officials have again urged veterinarians, local government officials and dog owners to keep on the look out as the tick is already well established there.

Queensland's chief veterinary officer Dr Allison Crook again asked veterinarians to submit samples for testing from dogs showing signs consistent with ehrlichiosis to help Biosecurity Queensland's surveillance program.

"Although they can vary considerably among dogs, symptoms typically include fever, lethargy, enlarged lymph nodes, loss of appetite, discharge from the eyes and nose, weight loss, and anaemia and bleeding disorders," Dr Crook said.

"To help prevent disease in dogs, dog owners should maintain an effective tick control program, avoid taking dogs into tick-infested area such as the bush where possible, and inspect dogs for ticks after being in tick-infested areas and carefully remove ticks.

"Ehrlichiosis is a nationally notifiable disease and anyone who suspects a dog is showing signs of the disease must report it immediately to the Emergency Animal Disease Watch Hotline on 1800 675 888."

The incubation period for the development of acute disease is about 1-3 weeks although the chronic form may not show any clinical signs until months or years after infection.

The disease has quickly spread throughout the NT "and is confirmed to be present in all communities" within the Roper Gulf Regional Council, according to council veterinarian Samantha Phelan.

"This is a devastating disease. Over the last three months, we have seen a tsunami of this sickness spread through dogs in the Katherine and Roper Gulf communities and it is spreading rapidly through the NT and Northern WA.

Dr Phelan said an infected tick only needs to be on a dog for one hour before transmission.

"Dogs quickly become very sick. They go off their food, become very lethargic, lose weight, often develop blue or cloudy eyes and develop clotting problems in their blood.

"While some dogs recover, many die quickly from bleeding that cannot be stopped or from a slower wasting sickness that ultimately kills them. It can be very traumatic for families and the veterinary staff looking after the dogs," Dr Phelan said.

She said if caught early, the sickness is often treatable by a vet.

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Prof. Irwin said public awareness was the best treatment against ehrlichiosis now.

"There is a report now of a case in Perth, it spreads so fast because people travel with their dogs."

He suggested coronavirus border road blocks slowed its spread last year.

"When you have the grey nomads moving up through the north, many of them take their dogs, that's where there'll be a lot of spread.

"This is an adaptable tick which can survive in all areas of Australia.

"We have been looking for it, expecting it would turn up eventually and now it is here.

"Every dog owner, not just those in tropical areas, need to pay attention."