Canine ehrlichiosis
Also called Canine monocytic ehrlichiosis (CME)
A tick-borne infection of white blood cells in dogs. Some dogs have no signs, others get fever, a low platelet count and bleeding, and chronic cases can lose all types of blood cells.
Cause and spread
- Cause
- The bacterium Ehrlichia canis.
- How it spreads
- By ticks, mainly the brown dog tick (Rhipicephalus sanguineus), which can live indoors in houses and kennels.
Signs to watch for
- Fever, lethargy and loss of appetite
- Swollen lymph nodes and spleen
- Pinpoint bleeds, bruising or nosebleeds
- Vomiting, diarrhoea, swollen legs
- Eye problems such as inflammation inside the eye
- Chronic form: weight loss, swelling, and low blood cell counts
Many diseases look alike. Only a laboratory test can tell them apart, so please see a veterinarian for any sick animal.
How it is diagnosed
A blood count often shows a low platelet count and sometimes low red and white cells. Stained smears can show the organism in white blood cells but cannot identify it for certain. PCR is now often used, but it can miss the organism in dogs that are chronically or silently infected.
- Usually the first testComplete Blood Count (CBC)Shows a low platelet count and other blood cell changes.
- Usually the first testBasic Haemoparasite Panel (CBC + Blood Smear) (panel)Blood count and blood smear together.
- Confirms the diseaseEhrlichia canis PCRDetects the bacterium's genes in blood.
- Supports the diagnosisBlood Smear ExaminationMay show the organism in white blood cells.
- Supports the diagnosisCanine Haemoparasite PCR ProfileRules in or out Babesia and Hepatozoon at the same time.
Prevention and control
- Use tick-control products, and remove ticks promptly
- Make surroundings less attractive to ticks, for example by clearing brush; ticks such as the brown dog tick can become established indoors in houses and kennels
- Check dogs regularly for ticks
Where this information comes from
- Ehrlichiosis and Anaplasmosis (factsheet) · Center for Food Security and Public Health, Iowa State University
General information for animal owners and veterinarians, last checked October 2026. It does not replace the advice of your veterinarian, who should decide which tests and treatment your animal needs.