Identify Ehrlichiosis Symptoms at All 3 Stages of the Disease Learn What Signs to Watch Out For

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Ehrlichiosis is a tick-borne disease with mild symptoms that can go undetected for many years, making it harder to cure. Early detection is key, so learn more here.

Ehrlichiosis is one of several tick-borne illnesses that can strike you and your furry friends. Arm yourself to fight it by learning as much as you can about ehrlichiosis symptoms.

Ehrlichiosis” refers to any of a group of diseases caused by bacteria in the Erhlichia group. Ehrlichiosis is usually transmitted by ticks, and can be quite serious, both for humans and dogs, though it’s rare among cats. Ehrlichiosis gets harder to treat the farther it progresses, so early detection is critical.


Ehrlichiosis has three different stages that have different symptoms and different prognoses. Since dogs get the disease much more often than cats, symptoms in dogs are much better understood. The first symptoms start one to three weeks after a dog is first infected.

Stage 1: Acute Ehrlichiosis Symptoms in Dogs


  • Fever
  • Sores in the mucous membranes
  • Inflammation of the blood vessels
  • Bleeding disorders (nose bleeds, for example)

Diagnosis: A simple blood test can confirm the presence of the bacteria.

Duration: The acute phase lasts two to four weeks.

Treatment: This phase can usually be cured with antibiotics.

Prognosis: Early detection, and treatment with antibiotics, can often result in complete eradication of the bacteria.

If neither antibiotics nor the dog’s own immune system fight off the bacteria, the disease seems to disappear, but actually moves into the second phase. Mild cases do sometimes go away on their own, without treatment.

Stage 2: Subclinical Ehrlichiosis Symptoms in Dogs

Symptoms: The subclinical stage of the disease has no symptoms at all.

Diagnosis: There are a number of blood tests and other tests vets can do to find out if the Ehrlichia bacteria are still in the dog, but none of them are reliable by themselves. Most can give false negative results, while some can also give false positives.

Duration: The subclinical phase can last up to five years before the symptoms of chronic infection develop.

Treatment: Subclinical ehrlichiosis can be cured with antibiotics as well, but might require extended treatment, and it is hard to be sure the treatment has been successful.

Stage 3: Chronic Ehrlichiosis Symptoms in Dogs

  • Pale gums (from anemia)
  • Swollen lymph nodes
  • Breathing problems
  • Coughing
  • Inflammation of the blood vessels
  • Increased urination and increased drinking (from kidney problems)
  • Eye problems
  • Lameness
  • Neurological problems including confusion, disorientation, and behavior changes

Prognosis: Chronic ehrlichiosis can be treated, but a cure at this stage is a bit of a long-shot. Chronic ehrlichiosis can be managed, but can ultimately lead to the death of your pet, usually from a related side effect.

Ehrlichiosis in Cats

Cats seem to have similar symptoms to dogs, as well as lethargy, weight loss, and an enlarged spleen, and sometimes hypersensitivity to light, noise, or other stimuli. Treatment is also similar to canine ehrlichiosis.

Can I Get Ehrlichiosis from my Cat or Dog?

You can catch ehrlichiosis, but not from your dog or cat. Ehrlichia travels by tick, and humans do not get the same kinds of Ehrlichia as dogs or cats. You could catch the human version of ehrlichiosis from a tick your animal brings inside, though. Learn how to avoid tick bites, how to thoroughly check yourself for ticks, and how to safely remove an embedded tick.

What Do I Do If My Dog or Cat Gets Ehrlichiosis?

The early symptoms of ehrlichiosis are very hard to catch, yet early diagnosis is critical. So do regular tick checks. If you find an engorged tick on any of your animals (or on yourself), freeze the tick in a sealed bag with the date on it. If the bite victim gets sick within the next three weeks, assume ehrlichiosis (or another tick-borne illness) is a possibility and go to the vet. Bring the tick, in case the vet wants to test it as well.

Antibiotics should cure the disease at this stage, but your pet may also need to be treated for secondary problems, like dehydration. In some cases, treatment won't ever clear the infection completely and it will become chronic.

The early symptoms are easy to miss. If your pet does develop chronic, or end-stage ehrlichiosis, your pet’s best chance will be antibiotics plus other supportive treatments such as blood transfusions and steroids.

More on Ticks

Types of Ticks in the U.S.
How to Stop Ticks
How Do I Find Ticks on My Pet?

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.

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