Babesiosis in Dogs

Babesiosis in dogs is a disease that is carried by ticks. It affects many systems in the body and it can make your dog very sick. 

Read on to learn more about Babesiosis in dogs, including what causes it, common signs to watch for, diagnosis, treatment, and prevention.

What Is Babesiosis?

Babesiosis is a blood-borne disease that is caused by a microscopic parasite called Babesia. Babesia are single-celled protozoan parasites that must live in a host to survive. Currently, a minimum of seven different Babesia species have been identified in our canine companions: B. canis, B. vogeli, B. rossi, B. gibsoni, B. conradae, B. vulpes, and B. negevi.

Babesia infections are found worldwide, wherever ticks are found (1). Babesiosis is called an emerging disease because it is diagnosed more frequently and in more places than it was historically. This may be due to increased numbers and range of ticks and/or dog importation around the world. 

How Do Dogs Get Babesiosis?

Dogs are infected with Babesiosis when they are bitten by a tick that is infected with the parasite. Ticks transmit the disease to dogs after the tick has bitten and attached to the dog for two to three days. Several species of ticks, including the brown dog tick and the American dog tick, appear to carry the parasite, and both dogs and cats are at risk. Humans can also contract Babesia infection. However, Babesia is not considered a zoonotic disease because the Babesia species that infect dogs and cats do not appear to infect humans.

Some species of Babesia, such as B. gibsoni, are also spread from dog to dog via dog bites, contaminated blood transfusion, or even in utero from mother to puppy via the placenta. Any age and breed of dog can become infected. However, Greyhounds seem to be predisposed to B. canis infections, and B. gibsoni infections are seen more often in American Pit Bull Terriers than other dogs. Dogs who are housed together in kennels where ticks are prevalent are at higher risk for becoming infected, as well as dogs who have had their spleen removed, have had chemotherapy, or have had a blood transfusion. 

Babesiosis Symptoms in Dogs

Incubation time for Babesiosis is two weeks. This means that dogs will not show symptoms until two weeks after infection. Babesiosis can be tricky to diagnose because the symptoms can mimic symptoms of other diseases and dogs can either present acutely with symptoms, have chronic waxing and waning symptoms, or have no symptoms at all.

Babesiosis attacks several systems in the body, including blood, lymphatic, immune, liver, and nervous systems. Babesia attack and destroy red blood cells leading to anemia, which causes symptoms. Babesia also cause mild to moderate liver inflammation. The most common symptoms associated with Babesiosis include:

• Low energy
• Loss of appetite
• Pale gums
• Weight loss
• Fever
• Enlarged lymph nodes and spleen
• Jaundice
• Collapse

Depending on the severity of disease, Babesiosis can also be implicated in acute kidney failure, low blood sugar, damage to heart muscles, pancreatitis, muscle pain, multiple organ dysfunction, and vision changes (2).

Some dogs carry the infection for years without any symptoms. These dogs are called carrier dogs because even though they are not affected by the infection, they can still transmit the disease to other dogs.

How Is Babesiosis in Dogs Diagnosed?

A veterinarian diagnoses canine Babesiosis with a combination of a history of recent tick exposure or dog bites, physical examination, and symptoms. They will then run laboratory tests based on their index of suspicion of a Babesia infection. These tests can include:

• Complete blood count to check red and white blood cells
• Microscopic examination of blood to look for parasites
• Serum biochemistry to check internal organ function, electrolytes, blood proteins, and some enzymes
• Urinalysis to check for kidney function and urinary health

If the vet suspects a tick-borne disease like Babesia, then they will want to run a few more specialized tests. These could include:

• Immunofluorescence Assay to check for antibodies against Babesia
• PCR to test for presence of Babesia DNA in the blood

If a dog who is housed in a kennel or multi-dog household is diagnosed with Babesia, all dogs in that household or kennel should be screened for Babesia because there is a higher percentage of carrier dogs within kennel situations. 

Babesiosis Treatment in Dogs

Babesia infections are treatable in dogs, however, treatment will vary depending on how sick the dog is. Severely affected dogs will need to be hospitalized. Dogs with mild disease can be treated on an outpatient basis. Dogs who have dangerously low blood pressure require fluid therapy. Severely anemic dogs may require a blood transfusion. 

• The only FDA approved treatment for Babesia are injections of Imidocarb dipropionate administered every 1-2 weeks. This treatment clears B. canis infections but may not completely clear B. gibsoni infections. 
• Combination oral treatment with azithromycin and atovaquone is the treatment of choice to potentially clear B. gibsoni infections. 

Additional medications that may be prescribed to clear the infection include:

• Clindamycin 
• Metronidazole
• Doxycycline
• Enrofloxacin
• Prednisone (to treat immune-mediated destruction of red blood cells)

Most dogs respond well to treatment within one to two weeks of starting medication. Prognosis is good to fair, depending on what body system is affected. Pet parents should also be aware that dogs who survive a Babesia infection may still be persistently infected without clinical symptoms and may relapse in the future. Because of this, never use dogs who have recovered from Babesiosis as a blood donor. 

One of the more important aspects of Babesiosis treatment is following up with your veterinarian after your pet starts treatment. Your vet will likely set up a series of recheck appointments after your dog has started medication. This will include laboratory tests to determine whether your dog’s red blood cell count is recovering and whether the parasite has been cleared from your dog’s body. Be prepared for recheck appointments to continue for several months, as dogs should be tested to ensure they are negative for the disease for two to three months after finishing treatment. 

Dogs who are infected with one tick-borne disease are sometimes infected with multiple tick-borne parasites. If your dog is failing to respond to treatment, then they may be carrying additional tick-borne diseases like Erhlichia, and need to be tested for that disease. 

How to Prevent Babesiosis in Dogs

Although there is a vaccine available in Europe against B. canis and B. rossi, this vaccine is not available in the States and may not protect against other Babesia species. The best way to protect your pets is by applying or administering an effective tick prevention medication on a regular basis when ticks are present, which can be year-round in many locations. 

Tick control is by far the most effective way to prevent Babesiosis in dogs and cats. If your dog frequents locations that are known to have ticks and/or wildlife, then check your dog for ticks regularly. If your dog does acquire a tick, then promptly remove the tick and keep it in a sealed container in case your vet wants to test it. 

Babesiosis is a serious disease, but fortunately it is relatively easy to prevent with strict tick control. In addition to protecting your dog against Babesia, tick control can help prevent other tick-borne diseases, several of which can be transmitted to people as well. Talk to your veterinarian about the best tick control for your dog.

References

1. Evason, ME. (2019). Babesia spp. (babesiosis). In S. Weese & M. Evason (Eds.), Infectious Diseases of the Dog and Cat: A Color Handbook (first edition, 201-204) CRC Press.
2. World Small Animal Veterinary Association World Congress Proceedings. “Update on the Complications and Management of Canine Babesiosis.” 2006. Retrieved from https://www.vin.com/apputil/content/defaultadv1.aspx?id=3859055&pid=11223