In this study, the evaluation of therapeutic effects of probiotic bacteria, in comparison with single supportive and symptomatic therapy. in CPV (canine parvovirus) infection was aimed. A total of 20 naturally infected dogs, 1-6 months old, exhibiting enteritis and for which the diagnosis were confirmed by an ELISA commercially available test, were randomly divided into two equal groups. Only supportive and symptomatic therapy was applied in group I, whereas a commercial probiotic product which contained different probiotic bacteria (VSL#3) was used as adjuvant oral therapy in the group II. Clinical scores established from complete clinical examinations performed at the beginning and on every subsequent day during the therapy and haematological parameters determined before and 5 days after treatments were compared between the 2 groups. A moderate anaemia (low haemoglobinemia) coupled to reduction in the mean corpuscular volume and haemoglobin concentration was evidenced in 55% of parvovirus infected clogs and a relatively leukopenia when compared with after the treatment was observed in all diseased animals. Seven (70%) and nine (90%) dogs in the groups I and II respectively, survived during the trial. Moreover, the clinical scores have declined significantly more rapidly in the group II than in the group I. While the erythrocyte parameters have not significantly differed between the 2 groups, leukocyte and lymphocyte numerations were significantly improved during the treatment course only in clogs additionally treated with probiotics. The present study indicates that probiotics may be beneficial in CPV therapy. especially for shortening the recovery time, under optimal care conditions.