Ehrlichiosis in Dogs: A Tick-Borne Threat

Ehrlichiosis is a bacterial disease in dogs transmitted primarily through the bite of infected ticks, specifically the brown dog tick (Rhipicephalus sanguineus), the American dog tick (Dermacentor variabilis), and the Lone Star tick (Amblyomma americanum). The causative agent is the bacterium Ehrlichia canis, although other Ehrlichia species can also cause infection.

How Ehrlichiosis Affects Dogs

Once a tick transmits the Ehrlichia bacteria, the bacteria invade the dog’s white blood cells. The disease progresses through three phases:

• Acute Phase: This phase occurs 1-3 weeks post-tick bite. Common symptoms include fever, lethargy, loss of appetite, enlarged lymph nodes, and possibly nosebleeds or bruising. Some dogs clear the infection during this phase.
• Subclinical Phase: This phase can last for months or even years. The dog may show no outward signs of illness, but the bacteria remain in the body, suppressing the immune system and potentially damaging organs. A complete blood count (CBC) might reveal abnormalities, such as low platelet counts.
• Chronic Phase: Some dogs develop chronic ehrlichiosis, a severe form of the disease. Symptoms are similar to the acute phase but more pronounced and can include weight loss, anemia, bleeding disorders, neurological signs (like seizures or incoordination), kidney disease, and eye problems (uveitis).

Recognizing the Symptoms

Early detection is crucial for successful treatment. Watch for these potential symptoms:

• Fever
• Lethargy
• Loss of appetite
• Enlarged lymph nodes
• Nosebleeds or bleeding gums
• Bruising
• Stiffness or lameness
• Eye problems (redness, cloudiness)
• Neurological signs (seizures, incoordination)

If you observe any of these symptoms, contact your veterinarian immediately.

Diagnosis and Treatment

Veterinarians diagnose ehrlichiosis through blood tests. These tests may include a CBC to look for abnormalities in blood cell counts, a biochemistry profile to assess organ function, and serological tests (e.g., ELISA or IFA) to detect antibodies against Ehrlichia. PCR testing can also be used to detect the presence of the bacteria’s DNA.

The primary treatment for ehrlichiosis is an antibiotic, typically doxycycline. The course of treatment usually lasts for several weeks. Your veterinarian may also prescribe supportive care, such as blood transfusions (in severe cases of anemia) or medications to manage specific symptoms like pain or inflammation. The prognosis is generally good, especially when treatment is started early in the course of the disease. Chronic cases may require longer treatment and have a less favorable prognosis.

Prevention is Key

The best way to protect your dog from ehrlichiosis is through tick prevention. This includes:

• Using year-round tick preventatives prescribed by your veterinarian (topical, oral, or collars).
• Checking your dog for ticks daily, especially after spending time outdoors.
• Removing ticks promptly and properly with tweezers, grasping the tick as close to the skin as possible and pulling straight out.
• Maintaining your yard by keeping grass short and removing brush and leaf litter.

Regular veterinary checkups and proactive tick prevention are essential for keeping your dog healthy and safe from tick-borne diseases like ehrlichiosis.