Piroplasmosis – why quick action is important

Piroplasmosis, also known as babesiosis, is a parasitic infection transmitted by ticks that is particularly prevalent in warm climates. Horses, dogs, and humans are all susceptible to this infection. If left untreated, the disease can be fatal.

INHALT
Cause and origin Symptoms Diagnosis Treatment Forecast Prophylaxis How to remove ticks correctly
Cause and origin

The disease is caused by two types of single-celled microorganisms, Babesia caballi and Babesia equi. The pathogens are transmitted to horses by various species of ticks. From the point of entry, the pathogens enter the bloodstream, multiply in the horse's red blood cells and destroy them.

Symptoms

After an incubation period (the time between infection and the onset of clinical symptoms) of 1 to 2 weeks, the first signs of the disease appear.

The disease can be peracute, acute, or chronic. The peracute form is characterized by sudden high fever followed by anaphylactic shock or pulmonary edema, which usually leads to death within 1 to 2 days. The acute course is characterized by fever, exhaustion, increased heart and respiratory rates, loss of appetite, pale or yellowish mucous membranes, and in some cases sweating and colic. The destruction of red blood cells releases red blood pigment, which can cause the urine to turn dark. Diarrhea may also occur as anemia progresses. The acute phase lasts 6 to 12 days. A chronic course is sometimes only evident through gradual weight loss, reduced performance, and recurring fever spikes. Slowly developing hind limb weakness can ultimately lead to the animal becoming recumbent.

In some animals, latent (not visible) infection, which can be lifelong, may occur after transmission of the pathogen. These horses are not sick, but they carry the pathogen and thus serve as a reservoir. The immune system reacts to the parasite by producing antibodies, which is why these "invisible" carriers can be identified with the help of certain blood tests. The disease can break out in stressful situations, as a result of a weakened immune system due to other diseases, or during pregnancy.

Diagnosis

Based on the clinical findings obtained by the veterinarian during the general examination and the information provided by the owner in the preliminary report, the veterinarian will be able to make a preliminary diagnosis. To confirm the diagnosis and rule out similar diseases, the veterinarian may perform various blood tests. During the acute infection, the pathogens can be detected directly under a microscope in a stained blood smear. However, the absence of Babesia does not rule out infection, as parasitemia (the presence of parasites in the blood) may have occurred before the clinical symptoms appeared. Special antibody tests can be used to determine whether a horse has already had contact with the pathogen. This also allows hidden carriers to be detected. The blood count also provides valuable information about damage to other organs, such as the liver, kidneys, and spleen.

Babesia in blood smear
Blood smear with Babesia (visible in red blood cells)
Treatment

In any case, immediate veterinary treatment is absolutely necessary if the above symptoms are detected. The type of treatment depends on the region in which the affected horse lives. In areas where piroplasmosis is widespread, the aim of treatment is to reduce the symptoms without completely eradicating the pathogen from the body. The reason for this type of treatment is that constant, low levels of the pathogen help the organism to build up a better and more lasting defense against the babesia. If such a horse is to be moved to a piroplasmosis-free area, it must of course be tested beforehand and possibly treated again. In regions where piroplasmosis is not normally present, the aim of treating infected animals is to completely eradicate the pathogen.

Different active ingredients can be used in both cases. Please discuss the exact procedure in each individual case with your veterinarian.

Forecast

The chances of recovery can vary greatly depending on the course of the disease. The prognosis for animals with peracute disease is poor, while animals with acute disease have a good chance of making a full recovery if the infection is detected and treated in time.

Prophylaxis

There is no vaccination to prevent the disease. The most effective protection against piroplasmosis infection is to prevent contact with ticks. Horses from endemic areas should be checked for ticks daily. Since the pathogen is not transmitted until 12 to 24 hours after the tick bite, potential infections can be effectively prevented by removing ticks immediately. Certain tick repellents can also be used on horses to protect them from tick contact.

The risk of disease can also be reduced with appropriate pasture management. A pasture without bushes and undergrowth, where the grass is kept short, is ideal for keeping ticks away.

How to remove ticks correctly

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 horse'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 thus more 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 fix 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.

Observe your horse for signs such as fever or fatigue over the next few weeks. If you suspect an infection, contact your vet immediately.