TICK FEVER/ CANINE ERHLICHIOSIS/ ERHLICHIA
 Is a tick borne disease of dogs caused by bacteria/ rickettsia that stays inside some cells of
dogs.
The causative agents are Erhlichia canis, Erhlichia platy and Ehlichia ewingii. E.canis has been
identified to be the most common cause of the disease.
The tick responsible for spreading the infection is Rhipicephalus sanguineus (brown dog tick).
STAGES OF THE DISEASE
1) ACUTE PHASE: starts from about 10- 20 days after tick bite and may last up to 4 weeks,
acute phase can resolve spontaneously.
2) SUBCLINICAL PHASE: may be ongoing for months to years and the immune system of the some
dogs (immunocompetent dgs) may be able to fight and eliminate the infection but in some dogs
the bacteria persist intracellulally leading to the chronic phase.
3) CHRONIC PHASE: this phase can present as mild or severe form of disease. Mild form the dog
can present with “just not feeling well”, weight loss, poor body condition (thin dog), not eating
well. Severe form of the disease can have the dog having bleeding tendencies, not eating or
vomiting, weight loss.
CLINICAL SIGNS OF AFFECTED DOGS—clinical signs differ according to the above different phases.
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Acute phase of disease – fever, weight loss, oculonasal discharge, poor appetite, with or
without generalised lymph node swelling (lymphadenopathy)
Chronic phase—dogs may show bleeding tendencies ( nose bleeding, gum bleeding, blood in
faeces), depression, weight loss, pale mucus membranes, difficulty in breathing, abdominal
pain, increased thirsty, large volume of urine (polyuria poly dipsia), painful joints, eye
problems such as bleeding, corneal edema.
ROLE OF A VETERINARIAN
 REACHING A DIAGNOSIS by using the above clinical signs and by DEMONSTRATING THE
ERHLICHIA PARASITE ON BLOOD (THIN BLOOD SMEAR) USING A MICROSCOPE or by sending
blood samples to the laboratory for tests.
 Also in treatment of sick dogs
TREATMENT AND PREVENTION OF THE DISEASE
DOXYCYCLINE, prednisolone / prednisone and bone marrow stimulants (androgenic steroids) usually
treat sick dogs with excellent prognosis.
Prevent the disease by TICK CONTROL. Several tick control methods can be employed with success
for example dog dipping, dog collars, dog shampoos, sprays, dog powders.