EN
During the last several years Babesia canis infections have become one of the most serious parasitic diseases of dogs in Poland, often leading to the death of the animals. Acute babesiosis manifests itself with fever, lethargy, lost of appetite, haemoglobinuria, and vomiting. However, some of the infections may be asymptomatic or insufficient treatment may lead to chronic, asymptomatic babesiosis. In the present paper, the case of a 2-year-old dog is described. The dog needed to undergo splenectomy after a spleen rupture during spontaneous play with other dogs. The likely cause for the spleen rupture was splenomegaly observed during USG and surgery. Several hours after surgery, babesiosis symptoms were manifested, with haemoglobinuria, fever and typical blood picture, morphology and biochemistry. The short time from the surgery to the manifestation of symptoms and observed splenomegaly suggested asymptomatic B. canis infection as an indirect cause of the spleen rupture.