Tick-Borne Disease in Dogs

What Is Tick-Borne Disease in Dogs?

Tick-borne diseases are a group of infections transmitted by ticks, which pick up infectious organisms, such as bacteria or protozoa, while feeding on wild animals like mice or birds. When a tick attaches to a dog, it can transmit the infectious organisms through its saliva into the dog’s bloodstream. Ticks must be attached to the dog for at least 24 to 48 hours to transmit an infection. Less commonly, dogs can contract a tick-borne disease by ingesting an infected tick. 

Tick-borne diseases are relatively common in certain US regions, but the widespread use of tick preventives by pet parents helps control overall infection rates. Ticks are most common in geographic areas that are heavily wooded and have tall grass, streams, or rivers. Ticks can be found throughout the United States, but high populations are present in the Southeast, Northeast, and Midwest, and on the West Coast.

Types of Tick-Borne Disease in Dogs

The most common tick-borne diseases in dogs include:

• Anaplasmosis

• Ehrlichiosis

• Rocky Mountain spotted fever

• Lyme disease (borreliosis)

• Babesiosis

• Hepatozoonosis

Symptoms of Tick-Borne Disease in Dogs

Dogs with a tick-borne disease may experience the following symptoms:

• Lethargy

• Decreased appetite

• Fever

• Enlarged lymph nodes

• Weight loss

• Lameness

• Joint pain

• Eye discharge

• Nasal discharge (can be bloody)

• Swollen legs or belly

• Skin bruising

• Pale gums

• Breathing difficulties

• Vomiting

• Diarrhea

• Bloody urine

• Muscle wasting

• Yellowing of the skin or eyes

Not all dogs with tick-borne diseases experience symptoms. Some dogs with strong immune systems are able to control the infection before symptoms develop. Young dogs, old dogs, and those with weakened immune systems may experience more severe disease.

A dog with a history of tick exposure who develops symptoms of a tick-borne disease should always see a veterinarian as soon as possible. Tick-borne diseases can progress quickly and can become fatal if left untreated. 

Causes of Tick-Borne Disease in Dogs

Dogs can contract a tick-borne disease following exposure to ticks, especially during the warmer months when ticks are generally more active.

Ticks can be found throughout the U.S.; however, certain geographic areas have higher populations due to the presence of heavily wooded areas, tall grass, and fields. Dogs living in or traveling to these areas are more likely to contract a tick-borne disease. Additionally, dogs who don’t receive year-round tick prevention medications are at an increased risk.

How Veterinarians Diagnose Tick-Borne Disease in Dogs

To diagnose tick-born disease in dogs, your veterinarian will start by collecting a thorough medical history of your pup, including any symptoms and when they began.

Discuss any recent travel history and potential tick exposure with your veterinarian during the visit. Your vet will also conduct a physical exam to check for abnormalities consistent with a tick-borne disease.

Because most tick-borne diseases have similar symptoms, diagnostic tests can help your veterinarian identify the cause. Tests that help diagnose tick-borne diseases include:

• Snap 4Dx: This simple in-office test requires only a few drops of your dog’s blood, and can within minutes diagnose Lyme disease, ehrlichiosis, and anaplasmosis.

• Serology: Serum, which is the liquid part of your dog’s blood, is sent to a veterinary diagnostic lab and tested for antibodies against tick-borne diseases.

• Blood smear: A drop of blood is spread on a glass slide, stained, and viewed under a microscope to check for signs of infection or infectious organisms.

• Polymerase chain reaction (PCR): A blood, joint fluid, or lymph node sample is sent to a lab for testing to diagnose tick-borne diseases.

• Blood work: Your vet may need to perform blood work to check your dog’s red and white blood cells, platelets, and internal organ function. While this test alone does not diagnose tick-borne diseases, it’s helpful to assess your dog’s overall health. 

• Urinalysis: Urine testing can help assess your dog’s kidney function and can identify protein in the urine, which may indicate a tick-borne disease.

Treatment of Tick-Borne Disease in Dogs

Treatment for tick-borne disease in dogs will depend on which tick-borne disease a dog has. In some cases, dogs may be infected with more than one tick-borne infection. Common treatments include:

• Antibiotics: An antibiotic called doxycycline is commonly used to treat Lyme disease, anaplasmosis, ehrlichiosis, and Rocky Mountain spotted fever. It is generally given for at least three to four weeks to eliminate the bacterial infection.

• Antiprotozoal medications: Dogs with babesiosis are treated with an antiprotozoal medication called imidocarb dipropionate. Hepatozoonosis is typically treated with pyrimethamine, as well as the antibiotics trimethoprim-sulfa and clindamycin.

• Anti-inflammatories: Some dogs may benefit from corticosteroids, such as prednisone, or non-steroidal anti-inflammatories (NSAIDs) to reduce inflammation and relieve pain and discomfort.

Dogs with severe disease often require hospitalization and supportive care. This may include:

• Intravenous (IV) fluids

• IV antibiotics

• Anti-inflammatories

• Appetite stimulants

• Oxygen therapy

• Anti-nausea medications

Dogs with severe anemia may require blood transfusions.

Recovery and Management of Tick-Borne Disease in Dogs

If appropriate treatment for tick-borne disease in dogs is started promptly after symptoms begin, pups generally recover from tick-borne diseases caused by bacteria, including Lyme disease, anaplasmosis, ehrlichiosis, and Rocky Mountain spotted fever.

Dogs typically start to feel better one to two days after antibiotics are started, but it can take weeks for them to make a full recovery. Babesiosis and hepatazoonosis are less predictable, and can be fatal despite treatment.

Unfortunately, some dogs with tick-borne diseases will experience lasting effects, such as joint pain or lameness, which persist for months or years after the initial infection. These dogs may benefit from long-term anti-inflammatories or pain medications to keep them comfortable. Hepatozoonosis is generally considered a lifelong infection because treatment does not completely eliminate the infectious organisms. Dogs with this disease will require ongoing management.

Always follow your veterinarian’s instructions regarding medications, at-home care, and follow-up visits to support a quicker recovery.

Prevention of Tick-Borne Disease in Dogs

You can protect your dog in several ways from tick-borne disease. Most importantly, use a topical tick preventive such as Simparica Trio™, NexGard®, or Revolution® year-round to prevent ticks from attaching to your dog.

When walking your dog, avoid areas with tall grass and woods to reduce the risk of tick exposure. Regularly scan your dog’s fur and skin for ticks and promptly remove any you may find.

Puppies over 8 weeks of age and adult dogs who are at risk for Lyme disease, such as those who live near wooded areas or in areas where the disease is prevalent, should receive the Lyme disease vaccine.