Mary Allen
The time has finally come: the long-awaited spring is here! The warm half of the year begins with daytime temperatures above the 10-degree mark and no frost at night. With the increase in temperatures in spring, however, the ticks also become significantly more active again. It is well known that ticks can transmit various pathogens. In the following, however, I would like to introduce you to one of these possible diseases, babesiosis. Unfortunately, there are many dubious and excessively exaggerated reports about this disease, which is also known as canine malaria or piroplasmosis. Therefore, I would like to show you what is really important with this disease and where obviously the horses have run away with some authors.
The Causative Agent of Canine Malaria
The disease is triggered by protozoa of the Babesia genus. They have specialized in their host and exist in different variants. Babesia canis, Gibson, and vogeli are relevant for dogs.
A distinction is made between the so-called large Babesia (B. canis and B. vogeli) and the small Babesia (B. gibsoni). An absolute peculiarity of these parasites is that they are transmitted within a tick to their offspring in the eggs of the ovaries. As a result, not only the adult ticks are infectious, but nymph stages can already transmit the pathogens of babesiosis.
From Travel to Domestic Illness
Until a few years ago, babesiosis was considered purely a travel sickness in this country, with which unprotected dogs could only become infected abroad, especially in the Mediterranean region. However, three factors have led to the fact that dogs can now easily become infected in Germany through the bite of an alluvial forest tick:
- Increased travel has brought ticks contaminated with Babesia to Germany
- Many untested imported dogs (including animal protection dogs from the former Eastern bloc such as Romania) carry the pathogen into the bloodstream
- Global warming due to climate change favors the spread and immigration of the transmitting tick species
How Does the Pathogen Get into the Dog?
Both the alluvial forest tick and the brown dog tick can act as carriers. Depending on the end of winter or the beginning of spring, both tick species are particularly active between March and May.
Since both tick species prefer a special environment, Babesia infections usually occur in so-called endemic areas. One speaks of an endemic disease when a disease frequently occurs in a limited area. During the act of sucking blood, the protozoa can be transferred to the host animal (dog). However, this usually only happens about 24 hours after initial contact.
Another route of transmission from dog to dog is blood transfusion. In the case of the small Babesia, a possible transmission from the mother bitch to her offspring has also been demonstrated.
In addition to babesiosis, ticks can also transmit other diseases in this country that were previously defined as pure travel diseases. These include Ehrlichiosis and Anaplasmosis.
What Happens in the Dog’s Body?
After successful infection, Babesia nest in the red blood cells of the host and thereby cause, among other things, the destruction of many red blood cells, which, in addition to inadequate oxygen transport in the blood, can lead to acute kidney and liver failure. Even if an infected dog appears to survive the disease, the immune system cannot usually eliminate all pathogens. As a result, dogs can become silent carriers who have no symptoms (any longer) but are still infectious. If a tick sucks its blood and later infects other dogs, it can transmit the ingested Babesia to other dogs and thereby infect it
What are the Symptoms of Canine Malaria in a Dog?
As a rule, the first signs appear about 5-7 days after a tick bite. The infected dogs usually show a clearly disturbed general condition with high fever, loss of appetite, pale mucous membranes, and exhaustion. You can pass reddish urine, have yellow skin and mucous membranes and, in severe cases, develop abdominal dropsy.
If the central nervous system is involved, paralysis and epileptiform seizures can occur.
If left untreated, acute to peracute babesiosis in dogs is usually fatal within 2-5 days of the onset of symptoms.
However, what symptoms a dog shows depends on many factors, such as the physical condition of the patient and the Babesia species.
How is Canine Malaria Diagnosed?
If there is a suspicion (preliminary report, symptoms, origin, or stay abroad), a corresponding blood test is initiated. In addition to an antibody level (from day 10 after infection), the result of the pathogen (also large/small distinction) can be detected by means of PCR.
In addition, the microscopic detection of Babesia in blood smears is possible. Prompt blood sampling is the be-all and end-all here. The point in time and the resulting early intervention can make a significant contribution to improving the prognosis.
How do You Treat Canine Malaria?
To show the therapy in detail here would go beyond the scope. In simple terms, however, one can say that the treatment depends on the type of Babesia detected (large vs. small) and the symptoms. For example, infection with B. vogeli will be initiated with imidocarb. If advanced anemia is diagnosed, a blood transfusion may probably be unavoidable.
Your vet will act accordingly or refer you and your dog to appropriate professionals.
How to Prevent Canine Malaria?
The focus used to be on avoiding the known endemic areas with dogs – primarily the central area (all areas south of the Alps). As mentioned above, however, the carrier ticks have long been at home in German-speaking countries. Therefore, the best prophylaxis is protection against ticks. The choice between various dosage forms (tablet, spot-on, or necklace) is growing from year to year, so it is easy to lose track. Which preparation you ultimately decide on is up to you.
A little tip: if you can’t decide at all, it’s best to ask your veterinarian how he can protect his dogs. Regular collection may also offer a certain amount of protection, but without exception, it must be carried out daily and very thoroughly because as described above, even the very small nymph stages can transmit the babesias within 24 hours. Incidentally, humans are also susceptible, but can only be infected by Babesia divergens and Babesia Ducati.