Babesiosis in dogs, also known as “canine malaria”, is caused by blood parasites (babesia) that infect and destroy red blood cells. The parasites are transmitted by ticks. While babesiosis (or piroplasmosis) in dogs was long considered a travel sickness that only occurred in southern countries, climate change in connection with the growing number of dogs imported from abroad has meant that the pathogens and their carriers are also native to Europe to let become. Acute babesiosis can kill the affected dog within a few days. You can find out everything about babesiosis in dogs in this article.
What are babesias?
The Babesia genus is one of the protozoa that multiply as parasites in the red blood cells of their definitive host and thereby destroy them. The Babesia found in dogs mainly belong to the species Babesia canis, which is divided into several subspecies with different intermediate hosts:
- Babesia canis canis: This highly infectious subspecies is responsible for most diseases in this country. The carrier of these protozoa is the alluvial forest tick, which has spread widely from North Africa via southern Europe, Hungary and Austria throughout Central Europe for several years.
- Babesia canis vogeli: The rather rare and milder infections with this subspecies occur after the bite of the brown dog tick, which has so far mainly been distributed in northern Africa and southern Europe.
- Babesia canis rossi: This subspecies is considered to be the most infectious Babesia species for dogs. So far, however, the transmitting tick species has only been found south of the Sahara on the African continent and has not yet played a role in this country.
There are also Babesia species that can be dangerous to other mammals or humans.
However, since the respective species are very host-specific, infection from dogs to humans or vice versa is impossible.
These are very small parasites that attack the red blood cells of their host animal (dog) as protozoa, multiply in them and finally destroy them.
Babesiosis: This is how the dog gets infected
Babesias need different types of ticks as intermediate hosts for their reproduction cycle, but they do not harm them. Their so-called sporozoites “slumber” in the tick until it attaches to a dog. The pathogens immediately migrate into the tick’s salivary gland and are then transferred via the tick’s saliva into the dog’s blood, where they multiply in the red blood cells (=erythrocytes) and finally destroy them.
As a rule, it takes between 12 and 72 hours from the bite of the tick to the transmission of the pathogen, which is why it is so important to examine the dog extensively for ticks after every walk and to remove them as soon as possible. However, Babesia can also be transmitted directly from one infected dog to another, for example through direct contact with blood or from the mother dog via the umbilical cord to the unborn puppies.
Symptoms of babesiosis in dogs
If the pathogen is transmitted through a tick bite or through direct contact, the first symptoms of the disease appear after an incubation period of around 5-7 days (in rare cases up to three weeks). The organism of the infected host animal (in this case the dog) tries to fight the pathogen via its immune system. Fever, loss of appetite and general fatigue are the first symptoms.
The destruction of the erythrocytes leads to anemia (=anaemia) with pale mucous membranes, blood can accumulate in the urine (reddish to dark brown colour). Organ damage to the liver, spleen, kidneys and digestive tract lead to other symptoms, such as jaundice. Accumulation of water (= edema) in tissues, organs (lungs) or joints can occur. Many dogs show central nervous system failures such as paralysis or seizures.
Depending on the severity of the infection, acute babesiosis can kill the dog within a few days. Especially very young, old or previously ill dogs are affected by such severe courses. In rare cases, infected dogs die after just one to two days without having developed any clear clinical symptoms at all.
In areas where Babesia and its carriers are particularly common, dogs often develop antibodies against the pathogen. Bitches pass this on to their puppies via their mother’s milk, so that they are largely protected against an acute illness, but not against the Babesia infestation itself. Such dogs then show an unspecific, chronic or subclinical course, but can pass the pathogens back to a sucking tick via their blood, which then infects other dogs again as a carrier. Poor nutritional status, recurrent episodes of fever or general exhaustion can be signs of chronic babesiosis.
Is babesiosis contagious to dogs?
Babesiosis or canine malaria is transmitted to the dog by tick bites and leads to severe symptoms of the disease within a few days to weeks, and in the worst case to the death of the dog.
Diagnosis of babesiosis
A few years ago, a previous stay in southern Europe was the first important indication of an infection with Babesia, but this is no longer the case today due to the increasing spread of the intermediate hosts to Central Europe. Dogs that have never left Germany are becoming ill more and more frequently. It is therefore important to think of babesiosis at the first non-specific signs of the disease.
If there is a suspicion that the dog has been infected with Babesia, the veterinarian will use other diagnostic options in addition to the usual general examination and questioning of the dog owner about the observed symptoms. The blood count shows the destruction of the red blood cells by a greatly reduced hematocrit value. Above all, the microscopic examination of a blood sample can usually provide direct evidence of the pathogen about a week after infection. The PCR detection provides information even earlier, which is usually carried out by an external laboratory. The detection of antibodies in the dog’s blood, on the other hand, is only possible later in the course of the disease and is therefore more useful in the case of chronic disease progression.
Treatment of babesiosis in dogs
The course of a Babesia infection, which is usually acute and life-threatening in our latitudes, makes it necessary to start therapy promptly. Depending on the severity of the symptoms, the dog must first be stabilized immediately before the actual therapy can begin. If severe anemia is present, a blood transfusion may be necessary.
To treat babesiosis, a drug containing the active ingredient imidocarb is administered subcutaneously to the dog. A second injection at an interval of two weeks usually leads to the death of all parasites and complete recovery of the patient if treatment is started in good time. It is important that the disease is diagnosed correctly at an early stage and that treatment is initiated as quickly as possible. Successful treatment with imidocarb leads to a dog’s immunity to babesia that lasts about one to two years. After that, he can get sick again if he comes into contact with the pathogen again.
What helps against Babesia in dogs?
If the dog is already suffering from babesiosis, treatment must be initiated as soon as possible. A drug with the active ingredient imidocarb kills the pathogens in the dog’s blood. As a preventative measure, the dog should be treated from spring to autumn with special preparations that keep ticks away or kill them immediately after they bite the dog. This prevents the transmission of Babesia via tick saliva into the dog’s blood.
Prevention of babesiosis infection
As a dog owner, you can significantly reduce the risk for your dog of contracting babesiosis or dog malaria by taking preventive measures. The first priority here is the best possible avoidance of tick bites. After every walk in the woods, fields and meadows, the dog should immediately be checked all over for these parasites. As a rule, it takes a while for the tick to find a suitable place on the dog where it sticks its proboscis through the skin and attaches itself. Since the tick is still very small at this point (about the size of a pinhead), it can easily be overlooked, especially in long-haired or densely haired dogs.
Better and more effective, on the other hand, is regular treatment of the dog with special preparations that are administered as a spot-on, collar or in tablet form, spread through the skin and deter ticks or kill them within a very short time after the bite. This prevents the transmission of sporozoites.
A vaccine for dogs has also been developed that offers some protection against at least some Babesia species. If the dog is going on vacation to a particularly risky area, such a vaccination can provide additional security. Although there is no 100% protection against infection, at least a mitigated course of the disease is achieved.
