EHRLICHIOSIS

Ehrlichiosis is a disease caused by rickettsial organisms --E. canis, E. equi, E. phagocytophilia, and E. platys (microscopic blood parasites). The disease affects primarily dogs and people and is extremely rare in cats. The disease is transmitted by the bite of a tick (Rhipicephalus sanguineus and Dermacentor variabilis).

There are three clinial phases (stages) of disease: 1) Acute—spreads from bite wound to the spleen, liver and lymph nodes. Most dogs recover without treatment and enter a subclinical state; 2) Subclinical—organism persists in the body; 3) Chronic—impaired bone marrow production and chronic illness. The incubation period is 1-3 weeks. While any dog breed can be infected, Doberman pinschers and German shepherds tend to have more chronic and severe forms of disease.

Clinical signs are numerous and depend upon the phase of the disease: lethargy, depression, anorexia, weight loss, fever, spontaneous bleeding due to thrombocytopenia (low platelets), respiratory distress, ataxia (stumbling), head tilt, uveitis (inflammation of the eye), lymphadenopathy (enlarged lymph nodes), anemia, scrotal and limb edema, splenomegaly (enlarged spleen), hepatomegaly (enlarged liver), arthritis (rare) and seizures (rare). Ticks are found in 40% of the cases, meaning that your dog can have this disease even if you do not see any ticks.

Diagnosis is based upon a positive serologic test result. Other clinical lab abnormalities may include thrombocytopenia (low platelet count), anemia (low red blood cell count), mild increases in liver and kidney values, hyperglobulinemia (increased immune proteins), hypoalbuminemia (low albumin), and proteinuria (increased protein in urine). Other laboratory testing may be required to rule out other differential diagnoses.

The disease usually responds very well to antibiotics. The earlier in the course of disease treatment is begun, the better the chance for complete cure. Your pet may appear well after only a few day of medication, BUT IT IS IMPORTANT TO CONTINUE GIVING THE DRUG FOR THE FULL TIME PERIOD or your pet may come down with the disease again. Some pets with severe anemia may require a life-saving blood transfusion and additional medications. Most dogs will test seronegative in 9 months; a positive titer suggests re-infection or ineffective response to treatment.

PREVENTION: When you and your pet venture into areas that may be infested with ticks, you should take precautions to avoid exposure. Apply repellents to yourself and regularly use flea and tick insecticides on your pet. Always closely inspect your pet and yourself after walking in woods, fields, or meadows. If you detect any ticks, do not crush the tick’s body during removal. Rather, use tweezers or forceps to grasp the tick’s head as close to your pet’s skin as possible, and gently remove the tick to avoid separation of the tick’s head from its body. There is no vaccine available to prevent this disease.

Note: This article is provided by Claws & Paws Veterinary Hospital® for informational purposes only.