The aim of this study was to assess the safety of a new vaccine, containing soluble parasitic antigen (SPA), against canine babesiosis. Fifteen dogs were included in the experiment. Five controls received only the adjuvant and 10 dogs were vaccinated with Babesia canis canis SPA twice, at a two weeks interval. For the whole period of the study all animals were under constant clinical observation. Haematological and biochemical tests were performed. Flu-like symptoms and local reactions at the injection site were observed in three animals from the vaccinated group and in two dogs from the control group. These events were transient, receded spontaneously and did not require any appropriate treatment. In 50% of the vaccinated dogs, a slight and spontaneously receding thrombocytopenia developed. However, in none of the animals used in the experiment shock symptoms were observed. Administration of the SPA did not affect the functions of internal organs, which was confirmed by normal results of biochemical tests. The obtained Babesia canis SPA can be considered safe and well tolerated by dogs, and therefore it can be used in further studies on the immunisation of animals against babesiosis.
