Babesiosis
Pathogen
Babesia canis (B. canis canis, B. canis vogeli), Babesia gibsoni -protozoan
Vector
Ornate dog tick (Dermacentor reticulatus) and Brown dog tick (Rhipicephalus sanguineus)
Geographical distribution
All of Europe except for the Nordic countries
Transmission
The life cycle of Babesia occurs between the dog and the tick. It very rarely infects cats. In dogs, asexual reproduction occurs when Babesia begin to multiply in the dog's red blood cells after the tick's feeding event. As they multiply, they destroy the red blood cells, and the new Babesia released into the blood infect new red blood cells, eventually entering a new tick during its blood meal. Sexual reproduction of Babesia takes place in the tick. The Babesia migrate from the tick's digestive tract to various cells to continue their transformation, ultimately ending up in the tick's salivary glands as sporozoites, waiting for the tick to feed again. Since Babesia also reproduce in the tick's egg and germ cells, the infection is directly transmitted to the tick's offspring. Babesia gibsoni can apparently also spread during dog fights or via the placenta without a vector, and this is considered the main transmission method for B. gibsoni in North Africa and Europe. The prepatent period (time from infection to when it can be diagnosed) for Babesia is usually 2-3 weeks.
Symptoms
Babesia causes hemolytic (red blood cell destroying) anemia in dogs, and babesiosis is classified into complicated and uncomplicated forms. The severity of the disease depends on the Babesia species infecting the dog, the dog's age and overall health before the infection. Babesia canis typically causes a more severe form of the disease compared to B. gibsoni. Uncomplicated babesiosis generally is limited to anemia, whereas the complicated form affects multiple organ systems.
​
In the complicated form, in addition to anemia, the dog may experience lethargy and fatigue, loss of appetite, increased heart rate, hemoglobinuria (blood in urine) and enlargement of the liver and spleen. The initial clinical signs often include pale or yellow mucous membranes, fever and general deterioration, which, if left untreated, can lead to neurological symptoms, complete collapse and death.
Prevention
Regular medication against ticks is recommended. There is a vaccine available for Babesia canis, but it is not available in Finland. Depending on the preparation, the vaccine can be administered as early as 5-6 months of age and must be renewed annually. The vaccine does not provide complete protection against infection but it can alleviate the symptoms of the disease.
References:
Saari S, Näreaho A, Nikander S. Canine parasites and parasitic diseases. 1.p. eBook, London, United Kingdom 2019
Solano-Gallego L, Sainz Á, Roura X, Estrana-Pena A, Miró G. A review of canine babesiosis: the Europian perspective. Parasites & Vectors 2016, 336.
Sykes J, Greene C. Infectious diseases of the dog and cat. 4.p. Elsevier Sounders, St. Louis, Missouri, Yhdysvallat 2011
Taylor M, Coop R, Wall R. Veterinary Parasitology. 4. p. John Wiley & Sons, Ltd, The Atrium, West Sussex, UK 2016