The microbial feed additive Bonvital is a preparation of Enterococcus faecium. The applicant is seeking authorisation of Bonvital as a feed additive for dogs at the dose of 1*109 CFU/kg of complete feedingstuff. The safety for the user and the environment has been considered in the context of previous opinions. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) has considered only the safety and the efficacy of Bonvital for dogs. A tolerance test was performed on adult dogs fed a diet to which Bonvital was added at 50 times the proposed dose. Although no adverse effects were observed on their immunological and haematological parameters, the inadequate experimental design did not allow the FEEDAP Panel to draw conclusions on the safety of Bonvital for dogs. Six experiments were provided examining the effects of the additive at use level in dogs. Two studies gave data on faecal consistency and four on immunological parameters. Microbiological parameters were also measured in one of these studies. The observation of reduced Clostridium perfringens counts and the results on faecal consistency do not support the functional group gut flora stabiliser. Data on immune response were inconsistent due in part to an inadequate experimental design and a lack of consistency in observations. Lymphocyte proliferation in response to a mitogen challenge was significantly greater in treated dogs in two studies, but it was not demonstrated that these animals will show an increased response to a specific antigen. Although there appeared to be a greater IgG response in vaccinated animals given Bonvital, this was seen only as an increase in total IgG in one study and as a specific IgG titer in one other study. Consequently the FEEDAP Panel was unable to identify any consistent immune response which might be considered beneficial to the animal.