Ehrlichiosis is a tick-born disease of dogs characterized by fever, lethargy, lameness and/or bleeding tendencies. It is caused by one of several rickettsial organisms that belong to the genus, Ehrlichia. Ehrlichia canis (E. canis) is the primary causative agent in dogs.

The disease is spread predominantly by the brown dog tick in the United States and is much more common in the dog than in the cat. It can be seen in any age dog, although it is seen most commonly in middle-aged animals. Purebred dogs, especially German shepherd dogs, appear to be more susceptible than crossbred dogs.

The impact on the affected individual can vary from very mild clinical signs to severe, life threatening disease. Several different stages of the disease are possible. Subclinical, asymptomatic infection may occur and may persist for months or years. Acute clinical signs may develop in some dogs and resolve spontaneously or with treatment. Acute infections may also develop into chronic infections that produce more severe clinical signs.

Diagnosis and Treatment Notes:

  • Ehrlichiosis is generally diagnosed by a serologic test to detect ehrlichia antibodies in the blood.


  • Treatment depends on the severity of the disease, your individual pet, and your veterinarian. Antibiotics are the mainstay of treatment for ehrlichiosis such as doxycycline, tetracycline or oxytetracycline. Discuss treatment details when your pet is diagnosed with this condition.


What to Watch for*:

  • Lethargy, depression
  • Anorexia, weight loss
  • Fever
  • Spontaneous bleeding from any part of the body (urine, stool, nose)
  • Bruising or small hemorrhages in the skin, gums, lips or around the eyes
  • Neurologic signs (poor balance, difficulty walking, tremors, seizures)
  • Squinting and inflammation of the eye, decreased vision
  • Swollen glands (enlarged lymph nodes)
  • Swollen and inflamed joints


*Please notify us if you notice any of the above signs or if you have any questions!