Ehrlichiosis (Tick Fever)
Description and Symptoms
What is canine ehrlichiosis?
Ehrlichiosis is an infectious disease of dogs transmitted by the bite of a tick. It first gained attention as a significant disease when military dogs returning from Vietnam during the 1960’s were found to be infected. The disease seems to be particularly severe in German Shepherds and Doberman Pinchers.
The organism responsible for this disease is a rickettsial organism. Rickettsiae are similar to bacteria. Ehrlichia canis is the most common species involved in ehrlichiosis, but occasionally, other strains of the organism will be found.
How does a dog get infected with ehrlichia?
Ehrlichiosis is transmitted to dogs through the bite of infected ticks; the brown dog tick is the main reservoir of the organism in nature.
What are the signs of ehrlichiosis?
Signs of ehrlichiosis can be varied and slow to develop.Common signs include fever, swollen lymph nodes, respiratory distress, weight loss, bleeding disorders, and, occasionally, neurologic disturbances. A simple
blood test can confirm infection.
What can be done?
Left untreated Ehrlicia can cause severe and even fatal disease. Fortunately most cases respond well to support and treatment if cuaght early. Please contact us if your pet shows any of the above signs or you have questions.
Diagnosis and Prognosis
How is ehrlichiosis diagnosed?
It may be difficult to diagnose infected dogs during the very early stages of infection. The immune system usually takes 2-3 weeks to respond to the presence of the organism and develop antibodies. Since the presence of antibodies to Ehrlichia canis is the basis of the most common diagnostic test, such dogs may be infected yet test negative. Testing performed a few weeks later will reveal the presence of antibodies and make confirmation of the diagnosis possible.
Rarely, the organism itself may be seen in blood smears or in aspirates of cells from lymph nodes, spleen, and lungs. This is a very uncommon finding. Therefore, detection of antibodies, coupled with appropriate clinical signs, is the primary diagnostic criteria.
How is ehrlichiosis treated?
Dogs experiencing severe anemia or bleeding problems may require a blood transfusion, initially. However, this does nothing to treat the underlying disease. Extended antibiotic treatment and retesting is critical to a positive outcome for your pet.
What is the prognosis?
Dogs with competent immune systems will usually recover, although they remain susceptible to reinfection. Dogs with weak immune systems and those which have progressed to the terminal stages of infection (bone marrow failure) have a guarded prognosis.
Can anything be done to prevent it?
Ridding the dog’s environment of ticks is the most effective means of prevention. We recommend using a monthly topical product to prevent tick attachment. Please contact us to determine which product is best for your pet.