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Ehrlichiosis in Dogs

Understanding Your Pet's Medical Diagnosis

What is ehrlichiosis?

Ehrlichiosis is a disease caused by an organism, called Ehrlichia, which is transmitted through the saliva of the Brown Dog Tick. Many different species of Ehrlichia are capable of infecting dogs and cats. The disease is diagnosed most frequently in geographical areas with natural tick populations.

What causes ehrlichiosis?

When the tick ingests a blood meal, the Ehrlichia organisms are transmitted through the tick saliva into the animal. The incubation period varies between one to three weeks. In some animals, the disease is subclinical and the animal appears unaffected. In acute ehrlichiosis, the organism can spread from the bite site to the internal organs causing inflammation and organ damage. Impaired bone marrow activity occurs in the chronic stages of ehrlichiosis, resulting in decreased production of platelets, red blood cells, and white blood cells.

What are the signs of ehrlichiosis?

The clinical signs of ehrlichiosis depend on the stage of disease. They include lethargy, depression, lack of appetite, weight loss, fever, and difficulty breathing. An animal in the acute stage of ehrlichiosis also may have enlarged lymph nodes, pinpoint bleeding spots (petechia) seen on the gums, and an irregular gait. The chronic stage of the disease often is characterized by anemia (low number of red blood cells), eye infections, spontaneous nosebleeds, bleeding in the retina of the eye, and swelling of the limbs.

How is ehrlichiosis diagnosed?

Ehrlichiosis can be diagnosed through serological testing that looks for antibodies (specific proteins) that are made by the body, in response to the infection. In addition, blood and urine tests are useful for determining the stage of this disease and assessing organ function. Clinically, an animal with acute ehrlichiosis may have low numbers of platelets and red blood cells. In some cases, microscopic analysis of a sample of bone marrow may be required.

How is ehrlichiosis treated?

The treatment of ehrlichiosis will depend on the severity and progression of the disease. Any ticks should be removed carefully from the animal. Some treatment options include antibiotics, steroids, fluid therapy, and blood transfusions. Blood work should be done at regular intervals to assess response to treatment and to monitor progress.

What is the prognosis for animals with ehrlichiosis?

The prognosis (outcome) for animals with ehrlichiosis is variable, depending on the stage of the disease. The prognosis for acute cases is good with appropriate treatment. However, the prognosis may be poor in chronic cases where the bone marrow is damaged severely.

General Information


Ehrlichiosis is a blood disorder caused by blood cell parasites called rickettsiae. Of the 4 different rickettsiae that can cause the disease, ehrlichia canis is the most common.

Dogs are infected when they are bitten by ticks carrying the rickettsiae or when they receive transfusions of blood contaminated with the rickettsiae. Signs of ehrlichiosis develop within 8-20 days.

The acute or early phase of the disease lasts 4-6 weeks and is characterized by such signs as weight loss, fever depression discharge from the eyes and nose, respiratory problems and enlarged lymph nodes. Many dogs recover after this stage of the disease. In other dogs, the infection causes subclinical signs of ehrlichiosis.

Dogs with subclinical ehrlichiosis may become chronically infected, showing depression, weight loss, hemorrhage, fever and various other organ problems.

Ehrlichiosis is diagnosed by blood tests. The disease is prevented by controlling tick infestation of the dog.

Important Points in Treatment

1. Ehrlichiosis usually can be treated, regardless of the stage of infection. However, the earlier the disease is detected, the more rapid is recovery. Chronically infected dogs may require treatment for several months. Dogs with severe anemia or hemorrhage may require blood transfusions.

2. Repeated blood tests are required during the treatment period.

3. Give all the medication as directed. Call the doctor if you cannot administer the medication.

4. Diet: Follow the instructions checked.

____ Feed the normal diet.
____ A special diet is required. Feed:

5. Water: Encourage your dog to drink water. Provide fresh water at all times. If your dog does not drink sufficient water, lightly salt the food until water consumption increases.

6. Exercise: Aside from short walks for elimination, keep your dog indoors and warm. Limit activity and do not encourage play until the dog is fully recovered.

7. Carefully examine your dog for ticks at regular intervals. Call the doctor if you cannot control tick infestation.

Notify the Doctor if Any of the Following Occur:

* Signs of disease worsen or recur after apparent recovery.

* Your dog refuses to eat or loses weight.

* You detect hemorrhage in you dog's gums, eyes or skin.

* There is a change in your dog's general health.