Babesiosis – why tick protection is so important

The pathogen that causes babesiosis in dogs is a single-celled blood parasite of the genus Babesia, of which at least nine different subspecies are currently known to be dangerous to dogs. The pathogen is transmitted to dogs by the ornate dog tick (Dermacentor reticulatus), which is now widespread throughout Central Europe. Once the tick has attached itself to the dog, the pathogen is released in the tick and passed on to the dog through its saliva. The pathogen can also be transmitted through blood transfusions.

After 48 to 72 hours, the babesia from the tick's saliva enter the dog's bloodstream and invade the red blood cells. After multiplying in the blood cells, the pathogens destroy them, are released, and can invade new, uninfected cells. Since the dog's immune system is only able to fight the pathogens incompletely, infected animals remain a constant source of infection and thus a reservoir for the pathogen.

After an incubation period of about five to seven days, rarely up to three weeks, the most common acute form of babesiosis in Germany occurs. The first signs of illness in affected animals are listlessness, weakness, loss of appetite, high fever, and pale to yellowish mucous membranes. As the disease progresses, the destruction of red blood cells leads to anemia and the excretion of red to green-brown urine due to the breakdown of hemoglobin. In severe cases, ascites (accumulation of fluid in the abdomen), bleeding of the skin and mucous membranes, inflammation of the stomach lining and muscles, or central nervous system disorders with epileptic seizures and movement disorders may also occur. If left untreated, the acute form leads to death within a few days due to kidney failure, anemia, and respiratory distress.

The severity of the disease depends on the dog's immune status and the type of Babesia. In areas with a high infection rate (= high prevalence of the disease), puppies receive antibodies through their mother's milk and in most cases only develop subclinical (= mild) or chronic infections with non-specific symptoms. They thus become chronic carriers without ever showing any obvious signs of the disease.

In order to diagnose babesiosis with certainty, various factors are important for the veterinarian. In addition to observing the clinical symptoms of the disease, which are sometimes very clear, it is extremely important to ask about any recent trips abroad and possible tick bites. Further blood tests can reveal other characteristic changes and thus provide very important information to confirm the diagnosis.

Direct detection of the pathogen can be carried out using blood smears or PCR (polymerase chain reaction), a method for replicating genetic material outside the organism. However, negative findings do not rule out infection, as pathogens are not necessarily detectable in the blood in subclinical or chronic cases. However, pathogen DNA can be reliably detected by PCR as early as three to five days after infection.

Since antibodies are not detectable until at least ten days after infection, indirect pathogen detection is not relevant in acute cases. In chronic cases, however, false results may occur because antibody levels are not always consistently high.

Due to its rapid and potentially fatal progression, babesiosis is always an emergency and should therefore be treated immediately by a veterinarian. The veterinarian has various medications available to kill the pathogen. Which drug is used and in what dosage always depends on the type of Babesia identified and varies depending on the region. In cases of severe anemia, additional supportive treatment measures such as blood transfusions or infusions may be necessary.

The prognosis depends on the course of the disease, the age of the dog, the strain of the pathogen, and how early it's diagnosed. If the dog's kidneys fail or they start bleeding a lot, the prognosis gets worse. If the dog goes into shock, there's almost no chance of recovery. But if the infection is caught and treated early, there's a good chance of a full recovery.

In many cases, however, even with consistent treatment, it is not possible to completely eliminate the pathogen and a later relapse must be expected. To assess the risk of recurrence, it may be advisable to have a direct pathogen test performed again a few months after the end of treatment.

Tick repellent is the most important preventive measure for protecting against babesiosis. Dogs should be checked for ticks regularly and any ticks removed after every outing. Various tick repellents and tick killers are available to prevent contact with ticks. These can be administered to dogs as spot-on treatments or collars. As there are certain breed-specific intolerances, please consult your veterinarian to determine which product is best suited for your dog.

A vaccine against two of the main types of babesia is available in Europe, but is still not available in Germany. The vaccine does not protect against the onset of the disease, but it significantly reduces its severity and prevents death. The vaccine is classified as a "non-core" component by the Standing Vaccination Commission for Veterinary Medicine (StiKo Vet), a committee of veterinary experts, and is therefore not considered a mandatory vaccination for dogs.

To remove the tick correctly and completely, always use tick tweezers or a tick card. Use these to grasp the tick as close to your dog's skin as possible. Pull the tick out slowly without twisting or squeezing it. If the tick is squashed or stressed by prolonged manipulation, it will release more saliva and pathogens. If the tick's mouthparts or head remain stuck in the skin after removal, this can lead to inflammation or allergic reactions.

Then thoroughly disinfect the bite area and your hands. Dispose of the tick by burning it or wrapping it in paper towels and crushing it. Alternatively, you can simply place it between two strips of adhesive tape. Then dispose of it in the household waste. If you want to know whether the tick is infected with babesia or other pathogens, send it alive in a well-sealed plastic bag by mail to a special laboratory.

Keep an eye on your dog for signs such as fever or tiredness over the next few weeks. If you suspect an infection, contact your vet immediately.