Canine ehrlichiosis

What is Canine ehrlichiosis?

Canine ehrlichiosis is a severe and sometimes fatal disease of domestic and wild dogs and foxes. It is caused by a blood-borne bacteria, Ehrlichia canis, which was first detected in dogs in the Northern Territory and Western Australia in May 2020. It is now established in dog populations in the Northern Territory (NT), the Kimberley, Pilbara and Gascoyne regions in Western Australia (WA) and the Anangu Pitjantjatjara Yankunytjatjara (APY) Lands in South Australia (SA).

Canine ehrlichiosis occurs worldwide and is a tickborne disease. In Australia, it is spread by the brown dog tick (Rhipicephalus sanguineus). Extremely rare instances of human infection have occurred overseas but have never been reported in Australia.

Canine erlichiosis is a notifiable disease in NSW under the Biosecurity Act 2015. This means that there is a biosecurity duty, or legal obligation, to notify authorities if you know or suspect that a dog has this disease. You may notify DPI in writing or by calling the Emergency Animal disease Hotline on 1800 675 888. Further details on how to report are provided in the Notifiable Pests and Diseases of NSW Primefact.  

Is there canine ehrlichiosis in NSW?

While the brown dog tick is known to occur in northern areas of New South Wales (NSW), no E. canis infections in dogs have originated in NSW to date. However, human-assisted movement of dogs from E. canis endemic areas have been shown to accelerate spread of the disease and represent a biosecurity risk for NSW.

Why is canine ehrlichiosis important?

If E. canis were to establish in brown dog tick populations in northern NSW it would be very difficult to control and would pose a significant health and welfare risk to domestic dogs and dingoes in those areas. Infected dogs may become acutely sick and need a prolonged course of antibiotics to treat the infection. While most dogs will recover, a proportion of these animals will remain infected, carrying the E. canis bacteria in their spleen and bone marrow indefinitely. An unpredictable proportion these “sub-clinical carriers” will develop chronic canine ehrlichiosis, which is usually unresponsive to treatment and fatal. Clinical signs are discussed in more detail in the Ehrlichia Canis Primefact .

What are my biosecurity responsibilities?

Under the Biosecurity Act 2015, there is a biosecurity duty, or legal obligation, to take measures to minimise the risk of introduction and spread of E. canis in NSW. Dogs relocating from or moving through E canis endemic areas are the most likely route of introduction of the disease to NSW. Measures you may take to discharge your general biosecurity duty are discussed in detail in the Ehrlichia Canis Primefact . Contact your veterinarian to develop a risk management plan for your dog.

Diagnostic testing of dogs from E. canis endemic areas prior to entry into NSW is strongly recommended. As there are currently no tests that accurately differentiate truly recovered animals from subclinical carriers, or to indicate which dogs are likely to develop chronic disease, dogs that have evidence of previous infection with E. canis are considered sub clinically infected and may pose a life-long risk of introducing the disease into NSW. Animals relocated from E. canis endemic areas should be accompanied (where possible) by records of where the dog is from, its medical and travel history, and whether the dog has been on an effective tick prevention treatment whilst in E. canis endemic areas. Owners of dogs potentially exposed to E. canis infection need to be aware of the clinical signs of chronic ehrlichiosis (see the Ehrlichia canis Primefact ) and should ensure there is an appropriate risk management plan in place.

How can I protect my dog from ehrlichiosis?

There is no vaccine available for ehrlichiosis and it can only be prevented by controlling ticks on dogs.

This may include:

  • Appropriate tick control for dogs travelling into areas where E. canis is known or suspected to occur. Note: adequate protection from E. canis generally requires a combination of products that your vet can recommend.
  • Ongoing appropriate tick control if your dog has originated from or travelled through an E. canis endemic area or if it has ever tested positive for E. canis, even if it is currently well.
  • Closely monitoring your dog for clinical signs and seeking prompt veterinary attention for diagnosis and treatment of E. canis.

See the fact sheets below or contact your veterinarian for more information.

Further information

Ehrlichia canis - Primefact

Veterinarians can download a copy of the Guidelines for veterinarians - Infection with Ehrlichia canis (Ehrlichiosis) (Northern Territory Government) (PDF, 292 KB).For suspect cases, NSW DPI will pay for the cost of the courier and the E. canis laboratory testing at Elizabeth Macarthur Agricultural Institute (see submission guidelines).

Ehrlichia Canis Surveillance Investigation Form (Dogs) (PDF, 173.2 KB)

Ehrlichia canis sample submission guidelines for veterinarians