EHRLICHIOSIS
Ehrlichiosis is an infectious disease of dogs first observed in military dogs returning from Vietnam during the 1970’s. Another name for this disease is “Tropical Pancytopenia.” The organism causing this disease is classified as a “rickettisa,” an organism similar to bacteria.
TRANSMISSION of this disease is through the bite of an infected tick. The brown dog tick is the main reservoir of infection in the U.S.
STAGES of the disease include acute (early disease), subclinical (no outward signs of disease), and chronic (long-standing infection). The acute phase lasts 2-4 weeks with signs including fever, swollen lymph nodes, respiratory distress, bleeding disorders, weight loss, and nervous system problems. At the conclusion of this stage, the subclinical stage begins. No signs of disease are present during this time. During this stage, the dog may continue to shed the organism, totally eliminate the organism from its body, or progress on to the chronic stage. The chronic stage results in anemia, blood clotting problems, lameness, eye problems, swollen limbs, and nervous system problems.
DIAGNOSIS can be difficult in the early stages. A blood test is available for diagnosis, but the test will not result in a positive reaction until 2-3 weeks after the organism has infected the pet. A repeat test in 3-4 weeks is often required to get a positive diagnosis.
TREATMENT begins with correcting severe anemia or bleeding problems, usually with a blood transfusion. Specific antibiotics, especially doxycycline or enrofloxin are most often prescribed for treatment. Treatment usually is required for 30 days. New research suggests that treatment for 2-4 months may be required.
PROGNOSIS is good provided the dog has a competent immune system. Dogs with weak immune systems, or in the last stage, which has affected the bone marrow, are less likely to survive.
PREVENTION. The elimination of ticks from the area is the best prevention.
HUMAN HEALTH SIGNIFICANCE. The disease is not contagious directly from a dog to a human. The only way the disease is spread is through the bite of a tick.
