Overview of Canine Ehrlichiosis
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.
Rickettsia are small microscopic organisms that are different from both bacteria and viruses. They enter various cells of the body and behave as tiny parasites, eventually killing the cell. Ehrlichiosis occurs worldwide, and it achieved prominence during the Vietnam War, when a large proportion of military dogs contracted the disease.
The disease is spread predominantly by the brown dog tick in the United States. Ticks are seen on the affected dog less than half the time, however. Infrequently, ehrlichiosis can be caused by the transfusion of infected blood. It occurs much more commonly 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.
What to Watch For
Symptoms of ehrlichiosis in dogs may include:
Diagnosis of Ehrlichia Infection in Dogs
Treatment of Ehrlichia Infection in Dogs
Depending on the severity of clinical signs, treatment options may include outpatient care or may necessitate hospitalization. Antibiotic therapy is the mainstay of treatment for ehrlichiosis. In severely ill patients, intravenous fluid therapy, blood transfusions, and other forms of intensive support may be indicated.
The most common antibiotics used to treat ehrlichiosis belong to the tetracycline family of drugs. They include doxycycline, tetracycline, oxytetracycline, and minocycline. These antibiotics have the greatest efficacy against Ehrlichia, and the fewest side effects.
Home Care and Prevention
At home, be sure to administer all medication exactly as prescribed and return for follow-up testing as directed by your veterinarian. Most antibiotics are given for at least two to three weeks for this disease. Prognosis with acute disease is excellent if caught early. Dogs in the acute phase of the disease often show improvement within 72 hours of starting the antibiotics. The prognosis with chronic cases varies, and dogs with chronic disease may require prolonged treatment.