What Is Ehrlichia in Dogs?


In this Article

  • What Is Ehrlichiosis in Dogs?
  • What Are the Symptoms of Ehrlichiosis in Dogs?
  • How Is Ehrlichiosis in Dogs Diagnosed?
  • What Is the Treatment for Ehrlichiosis in Dogs?
  • How Can I Prevent Ehrlichiosis in My Dog?
  • How Do I Check for Ticks on My Dog?

Ehrlichia in dogs is a bacterial disease that causes fever, bleeding, poor appetite, and lethargy. It’s a disease dogs get from ticks. Though this disease happens everywhere, it is more common in tropical regions. The disease can be severe and sometimes needs months of treatment. Prevention is important because this infection can be fatal.

What Is Ehrlichiosis in Dogs?

Ehrlichia are rickettsiae, a type of bacteria that live inside cells. The disease they cause is known as ehrlichiosis. Several types of Ehrlichia cause disease in dogs, but two species are common — Ehrlichia canis and Ehrlichia ewingii.

These bacteria live in ticks. When these ticks bite your dog, the bacteria in their saliva cause an infection. Several tick species can carry this infection. The common ones are the brown dog tick, the lone star tick, the American dog tick, and the black-legged tick. Ticks transmit infection after attachment to your dog for several hours.

Ehrlichia invade monocytes, which are cells of your dog’s immune system. Some species also attack the platelets which are needed for blood clotting. Ehrlichia in dogs can cause reduced platelet counts (thrombocytopenia) and bleeding.

What Are the Symptoms of Ehrlichiosis in Dogs?

Ehrlichia symptoms can be immediate (acute) or long-term (chronic). Acute symptoms occur 7 to 21 days after the tick bite and are therefore common in summer, when ticks are active. Common symptoms are:

  • Fever
  • Lymph node swelling
  • Limping and stiffness
  • Reluctance to walk
  • Reduced appetite
  • Tiredness
  • Cough and breathing difficulty

Your dog will most likely recover from this acute disease. Deaths are uncommon in young, healthy dogs if the ehrlichiosis diagnosis is made early. 

The chronic disease can appear in any season. Your dog may have some or all of these symptoms:

  • Enlarged spleen and lymph nodes
  • Low platelet counts and bleeding from the nose, skin, gums, or in the stools or urine 
  • Kidney failure
  • Brain and spine problems — partial paralysis, lack of coordination, and depression
  • Weight loss
  • Lameness that may shift from one limb to another

How Is Ehrlichiosis in Dogs Diagnosed?

If you notice your dog is not eating well, is lethargic, or has other symptoms of ehrlichiosis in dogs, you should visit your veterinarian. If your dog has been in a tick-infested area or has lived in a kennel or boarding facility, your veterinarian will order tests to diagnose ehrlichiosis.

Some of the tests that help in ehrlichiosis diagnosis are: 

  • A complete blood count (CBC). The usual findings are a low hemoglobin level (anemia, which reduces the oxygen carrying capacity of blood) and low platelet counts (thrombocytopenia, which can cause bleeding).
  • Ehrlichia antibodies by serology tests. These remain positive for years, even after the infection has been cured.
  • Polymerase chain reaction (PCR). This test is positive only during the active phase. It becomes negative after successful treatment.
  • Blood cultures are the definitive diagnostic test. Growing the bacteria in the laboratory is a sure diagnosis. Results do take up to 8 weeks to receive.

What Is the Treatment for Ehrlichiosis in Dogs?

Antibiotics are used to clear up ehrlichiosis in dogs. The most commonly used are doxycycline and minocycline, drugs of the tetracycline class of antibiotics. Other drugs recommended by the American College of Veterinary Internal Medicine (ACVIM) are chloramphenicol, imidocarb dipropionate, and amicarbalide. Recovery is excellent in acute ehrlichiosis treated early. Fever usually subsides in a day or two, but treatment should be given for 28 days.

If the infection is longstanding (chronic ehrlichiosis), the recovery is not sure. Prolonged courses of antibiotics are needed. Symptom relief happens in a few days, but blood abnormalities may last for months. 

If the infection has caused your dog to lose a lot of blood, your veterinarian may order a blood transfusion. This transfusion may be whole blood or platelet concentrate.

How Can I Prevent Ehrlichiosis in My Dog?

This infection can cause severe disease, and it’s best to take appropriate precautions to keep your dog safe:

  • Consult your veterinarian about a tick control program for your dog if you are living in, or traveling to, areas where ticks are present. This could include tick-repellent collars and similar devices to prevent ticks from attaching to your dog, and regularly giving them tablets and chews meant for tick control.
  • Avoid taking your dogs to tick-infested areas.
  • After returning from a tick-infested area, inspect your dog carefully for ticks for several days.
  • If you live in a tick-infested area, you should inspect your dog for ticks every day. 

Keeping your dog safe from ticks will also prevent other tick-borne diseases like  Lyme disease, Rocky Mountain spotted fever, and tularemia.

How Do I Check for Ticks on My Dog?

If your dog has been exposed, you should examine them for ticks. The common areas that ticks attach are:

  • In and around the ears
  • Around the eyelids
  • Between the toes
  • Under the front legs
  • Between the hind legs
  • Around the tail
  • Under the collar

If you see a tick on your dog, remove it with fine-tipped tweezers. Grasp the tick’s head as close to your dog’s skin as possible and pull it straight off. You should never grasp or squeeze a tick’s body when it is attached to your dog. 

For your own safety, you should wear gloves when inspecting your dog for ticks and removing them. Thorough hand washing is also good practice.

Your dog can’t give you this disease, but can bring ticks into the home. Some species of Ehrlichia can cause human disease. Older people and those with reduced immunity may get severe disease. Preventing tick bites, taking steps to keep ticks off your pets, and  keeping your yard tick-free can safeguard your pets and family.

Show Sources


American Kennel Club Canine Health Foundation: “Canine Ehrlichiosis.”

Centers for Disease Control and Prevention: “Ehrlichiosis.”  “Preventing ticks on your pets.” 

Companion Animal Parasite Council: “Ehrlichia spp. and Anaplasma spp”

Journal of Veterinary Internal Medicine: “Consensus Statement on Ehrlichial Disease of Small Animals from the Infectious Disease Study Group of the ACVIM.” 

McQuiston, J. Merck Veterinary Manual, “Ehrlichiosis and Related Infections in Dogs” Merck & Co., 2020. 

National Pest and Disease Outbreaks: “Ehrlichiosis in dogs.” 

Pathogens: “Serologic and Molecular Diagnosis of Anaplasma platys and Ehrlichia canis Infection in Dogs in an Endemic Region”

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