Dog Tick Diseases to Watch For: Ehrlichiosis and Anaplasmosis

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Tick-borne diseases you should know of.

When it comes to tick-borne diseases in dogs, Lyme disease  tends to dominate the conversation. But other common tick-borne diseases, like ehrlichiosis and anaplasmosis, can pose serious health risks to your dog and you. And with cases of ehrlichiosis in dogs and anaplasmosis in dogs on the rise in the United States, it’s increasingly important to be aware of signs, symptoms and treatments for both.

Ehrlichiosis in Dogs

Ehrlichiosis is an infectious disease transmitted by ticks carrying bacteria in the Ehrlichia genus. One of the most common Ehrlichia bacteria in the United States (Ehrlichia canis), is carried by the brown dog tick. While Ehrlichia canis is considered endemic in the southeastern and southwestern states, the brown dog tick can be found throughout the United States and Canada. The bacteria infects white blood cells and impacts blood platelets. The disease appears to be particularly severe in Doberman pinschers, German shepherds, Belgium Malinois and Siberian huskies.

Symptoms of Ehrlichiosis in Dogs

Symptoms of Ehrlichiosis in dogs present in three phases: acute, subclinical and chronic.

Acute Phase

  • Fever
  • Swollen lymph nodes
  • Loss of appetite
  • Lethargy
  • Respiratory distress
  • Bleeding disorders (including nosebleeds)

Subclinical Phase

If not treated or eliminated by the dog’s immune system, the illness will pass into the subclinical phase. This phase is considered the most dangerous phase as the disease does not present any symptoms, making it undetectable and able to progress without treatment.

Chronic Phase

If the infection remains untreated, it will enter the chronic phase. In this phase symptoms will become more intense and more difficult to treat. These symptoms include:

  • Anemia
  • Lameness
  • Bleeding episodes
  • Swollen limbs
  • Vision loss

How Is Ehrlichiosis in Dogs Diagnosed?

Your veterinarian will diagnose ehrlichiosis by considering tick exposure and running a series of diagnostic tests, including testing for antibodies in the blood. Diagnosis can be difficult early in the infection and can be furthered complicated by infection of other tick-borne illnesses.

A great way to help curb tick-borne illnesses is by reducing your dog’s exposure to these pests. Preventive care can act as a barrier against ticks, and therefore any diseases they may carry in their bite. Luckily, treatment options are available if your dog is diagnosed.

Treating Ehrlichiosis in Dogs

Antibiotics like doxycycline are quite effective in treating ehrlichiosis, especially when it is diagnosed in the acute phase. A long treatment course of about a month is required. Depending on your dog’s symptoms, other treatments, including steroids, may be needed.

Anaplasmosis in Dogs

Like ehrlichiosis, anaplasmosis is a tick-borne disease that infects a dog’s bloodstream. The most common form of the disease, Anaplasma phagocytophilum, infects white blood cells and is transmitted by deer ticks. A less common form, Anaplasma platys, affects blood-clotting platelets and is transmitted by the brown dog tick.

Symptoms of Anaplasmosis in Dogs

Dogs suffering from anaplasmosis may display a range of nonspecific symptoms beginning up to a week after infection. Anaplasmosis symptoms may include:

  • Fever
  • Lethargy
  • Lack of appetite
  • Malaise
  • Joint pain and lameness
  • Vomiting
  • Diarrhea
  • Coughing
  • Labored breathing
  • Seizures
  • Ataxia (lack of muscle and movement control)

Diagnosing Anaplasmosis in Dogs

Because its symptoms are similar to Lyme disease and other tick-borne illnesses, it can be difficult to diagnose anaplasmosis. Blood tests like enzyme-linked immunosorbent assay (ELISA), indirect fluorescent antibody (IFA), and polymerase chain reaction (PCR) tests can pinpoint specific antibodies to get to a diagnosis.

Like ehrlichiosis, preventive care is crucial in protecting your dog from anaplasmosis. Luckily, if you or your vet do notice symptoms, treatment is available.

Treating Anaplasmosis in Dogs

A 30-day course of doxycycline, the same antibiotic used to treat other tick-borne infections, will likely be prescribed for dogs diagnosed with anaplasmosis, and symptoms may show signs of improvement within 24 to 48 hours.

Can My Dog Give Me Anaplasmosis?

While it is technically a zoonotic pathogen, meaning it can spread from animal to animal and animal to human, it is highly unlikely you will contract anaplasmosis directly from your dog. However, a dog exposed to ticks could bring one carrying the bacteria into the home, where they could bite and infect you.

Preventing Ehrlichiosis and Anaplasmosis in Dogs

Year-round tick-prevention treatments like Credelio® (lotilaner) are the best way to protect your dog from ehrlichiosis, anaplasmosis and other tick-borne illnesses. But because no tick prevention method is 100% effective, it’s important to physically check for ticks after being in areas where ticks are known to live.


  1. “Ehrlichiosis in Dogs” (May 9, 2022). PetMD.

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Indications for Credelio

Credelio kills adult fleas and is indicated for the treatment and prevention of flea infestations and treatment and control of tick infestations (lone star tick, American dog tick, black-legged tick and brown dog tick) for one month in dogs and puppies 8 weeks and older and 4.4 pounds or greater.

Important Safety Information for Credelio

Lotilaner is a member of the isoxazoline class of drugs. This class has been associated with neurologic adverse reactions including tremors, incoordination and seizures. Seizures have been reported in dogs receiving this class of drugs, even in dogs without a history of seizures. Use with caution in dogs with a history of seizures or neurologic disorders. The safe use of Credelio in breeding, pregnant or lactating dogs has not been evaluated. The most frequently reported adverse reactions are weight loss, elevated blood urea nitrogen, increased urination and diarrhea. For complete safety information, please see Credelio product label or ask your veterinarian.