By Hannah Reid · Updated August 2026. General information only, not a substitute for veterinary advice. Sources are linked throughout; always consult a licensed Australian vet for diagnosis or treatment specific to your dog.
A tick-borne disease that is still moving south
Most Aussie dog owners know to check the coat for paralysis ticks after a bush walk. Far fewer have heard of ehrlichiosis — a bacterial infection carried by the brown dog tick, first found in Australian dogs in 2020 and spreading across the country ever since. With spring lifting tick activity and many dogs heading north with their families, it pays to know what this disease looks like and how to keep your dog safe.
What is ehrlichiosis?
Ehrlichiosis is caused by a bacterium called Ehrlichia canis, which infects a dog’s white blood cells. Dogs do not catch it from one another — it spreads only through the bite of an infected brown dog tick (Rhipicephalus sanguineus, recently reclassified as R. linnaei). An attached tick can pass the bacteria on within a few hours, which is exactly why prompt tick removal matters so much.
Australia was free of the disease until May–June 2020, when it turned up in dogs around Katherine and west of Alice Springs, per the RSPCA Knowledgebase. Because it is not native here, ehrlichiosis is a nationally notifiable disease, and Queensland owners have a general biosecurity obligation to help stop it spreading.
Where is ehrlichiosis in Australia now?
The spread has been steady. By early 2021, more than 300 dogs across Western Australia and the Northern Territory had tested positive. It is now endemic across the NT and has reached far north South Australia. In Queensland, infected areas by early 2024 included Mount Isa, Cloncurry, Townsville, Palm Island and Mareeba, and authorities warn it could push further into Queensland and New South Wales wherever the brown dog tick lives.
Signs to watch for
Ehrlichiosis can look different from one dog to the next, and some dogs carry it for months with no obvious signs. Vets generally describe three phases:
| Phase | Timing | What you might notice |
|---|---|---|
| Acute | About 1–3 weeks after a bite | Fever, tiredness, off food, swollen glands, weepy eyes or nose |
| Subclinical | Months to years | Often no visible signs, but the infection is still there |
| Chronic | Months to years later | Weight loss, weakness and bleeding problems — nosebleeds, or red spots and bruising on skin and gums |
Take the bleeding signs seriously: cloudy or sore eyes, nosebleeds, or tiny red patches on the gums or belly all warrant a vet visit.
When to call your vet (quick checklist)
- Your dog lives in, or has travelled to, a known ehrlichiosis area (northern WA, the NT, far north SA, or northern and central QLD) and seems unwell.
- You find an attached tick, especially after time in long grass or bushland.
- Fever, lethargy or loss of appetite that is not shifting.
- Any bleeding you cannot explain — nosebleeds, bruising, or red spots on the skin or gums.
- Cloudy, red or weepy eyes.
If you see the bleeding signs, treat it as urgent. Suspected cases can be reported via your vet or the national Emergency Animal Disease Watch Hotline on 1800 675 888 (RSPCA NSW).
How to protect your dog
There is no vaccine for ehrlichiosis, so prevention means keeping ticks off your dog:
- Keep your dog on a year-round tick-control product — vets commonly use chews such as Bravecto, NexGard or Simparica, or a Seresto collar. Ask your vet which suits your dog.
- For the brown dog tick, some vets favour products that repel or kill ticks before they bite, such as a Seresto collar or Advantix spot-on, which one clinic notes can help prevent transmission.
- Check your dog daily, running your fingertips over the skin around the lips, gums, head, ears, neck and chest.
- Before travelling north, talk to your vet about prevention and keep your dog out of tick-prone bush and long grass.
- Found a tick? Ask your vet how to remove it safely rather than yanking it out.
If you are brushing up on ticks in general, our guides to paralysis tick prevention and year-round tick and flea protection are worth a read. And because there is no shot for ehrlichiosis, it is a good reminder to keep the rest of your dog’s vaccinations up to date too.
Treatment and outlook
The reassuring part: ehrlichiosis usually responds well to antibiotics when it is caught early — typically a tetracycline such as doxycycline, given for at least four weeks. One clinic describes doxycycline as a simple, inexpensive treatment with a good recovery when started promptly. Left untreated, the chronic phase is often fatal. As with every tick disease, the sooner you act, the better your dog’s chances.
Frequently asked questions
Can I catch ehrlichiosis from my dog?
Not directly. The infection is not passed from dogs to people; rare human cases are linked to tick bites, not to dogs. Controlling ticks still protects the household.
Is there a vaccine?
No. There is currently no vaccine in Australia, so tick prevention is your main line of defence.
My dog rarely leaves the suburbs — is it still at risk?
The brown dog tick is found across all states and territories, though risk is highest in and around known affected regions. Year-round tick control is sensible wherever you live, and especially before a trip north.
Key takeaways
- Ehrlichiosis is a brown-dog-tick disease, first found in Australian dogs in 2020 and still spreading south; it is nationally notifiable.
- Watch for fever, weepy eyes and any unexplained bleeding, and see a vet quickly.
- There is no vaccine — year-round tick control and daily checks are the best protection, and early antibiotic treatment usually works well.
Sources: RSPCA Knowledgebase; RSPCA NSW; Business Queensland; Dogs Australia; Walkerville Veterinary Clinic.
