What is Ehrlichiosis?

Ehrlichiosis is a disease caused by a type of bacteria called Ehrlichia and is commonly transmitted by ticks. The disease is also known as ‘tracker dog disease’, ‘tropical canine pancytopenia’, ‘canine hemorrhagic fever’ and ‘canine typhus’. Ehrlichia bacteria initially infects white blood cells.

What are the symptoms?

The symptoms and severity of the illness depends on the type of Ehrlichia bacterial infection and the immune response of the dog. The two-main species of Erlichia effecting dogs are Erlichia canis and Erlichia lewinii.  Erlichia canis is more commonly diagnosed and tends to produce the most severe illness. Infection generally goes through three stages. The first, acute, phase develops 1-3 weeks after a bite from an infected tick and lasts 2-4 weeks.  The bacteria enter the white blood cells where it reproduces and can go on to infect the lymph nodes, spleen, liver and bone marrow. Platelets can also be destroyed effecting the bloods ability to clot. Your dog may exhibit all or some of the following symptoms,

• Fever
• Depression
• Lethargy
• Loss of appetite
• Weight loss
• Bruising
• Abnormal bleeding (nose bleeds)
• Joint pain and stiffness
• Enlarged lymph nodes
• Enlarged spleen
• Enlarged liver

Many dogs will fight off the infection but if not, he will enter the subclinical phase.  The dog may appear normal, maybe only showing slight anaemia. This phase can last months or even years until his body eventually destroys the bacteria. If he has been unable to eliminate the bacteria from his body he may progress to the chronic phase. Signs of chronic infection are: –

• Anaemia
• Neurological symptoms (e.g. depression, paralysis, seizures)
• Inflammation of the eyes
• Abnormal bleeding
• Severe weight loss
• Fever
• Shortness of breath

What are the causes?

Ehrlichia canis and Ehrlichia lewinii bacteria are transmitted by ticks worldwide, in areas where the brown dog tick and the Lone Star tick can be found.   The tick will feed on a dog infected with the bacteria then feed on another animal, passing on the Ehrlichia to that dog.

 What are the risk factors?

Dogs living in areas where ticks are prevalent and Ehrlichiosis is common, are most at risk.  Some breeds such as German Shepherds and Doberman Pinchers are prone to more serious chronic infections.

How is Ehrlichiosis in my dog diagnosed?

A combination of symptoms, a history of your dog’s health, recent activities, general living environment as well as blood and urine tests, will be used to make a diagnosis.

What treatment will my dog receive?

Your vet will treat ehrlichiosis with antibiotics and treatment will last for 3-4 weeks.  Some dogs may need a blood transfusion or intravenous fluids, depending on the severity of the disease.

What are the long-term effects of Ehrlichiosis?

If proper treatment is received during the acute phase, prognosis is good and your dog should make a full recovery. If the disease is not detected until the chronic phase, prognosis is poor.

How can I prevent my dog from developing Ehrlichiosis?

As there is no vaccine for ehrlichiosis. Avoiding exposure to ticks is the best way to prevent infection. Use products which repel and kill ticks such as tick collars and monthly preventative treatments. Particularly during peak tick season, avoid woods and tall grass and check your dog daily for ticks (it is believed a tick must feed for 24-48 hours to spread Ehrlichia).