Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed （FEEDAP� was asked to deliver a scientific opinion on the safety and efficacy of Lactobacillus acidophilus D2/CSL when used in feed for cats and dogs at a minimum dose of 5 �� 109 co lony forming units （CFU�?kg complete feedingstuffs. The additive is a preparation of viable cells of Lactobacillus acidophilus CECT 4529. This species is co nsidered by the European Food Safety Authority to be suitable for the qualified presumption of safety （QPS� approach to establishing safety for the target species and the environment. The safety of L. acidophilus CECT 4529 was assessed by EFSA in 2014. Following the QPS approach to safety assessment, L. acidophilus CECT 4529 is assumed to be safe for the target species and the enviro nment without the need for further studies. No co ncerns are expected from other excipients present in the product, so Lactobacillus acidophilus D2/CSL is also co nsidered safe for target animals, including cats and dogs, and the environment. The safety of the additive for the user was also co nsidered in that opinion. The FEEDAP Panel is unaware of any new data that would lead it to revise its co nclusions that the additive should be co nsidered to be an eye/skin irritant and a skin/respiratory sensitiser. Lactobacillus acidophilus D2/CSL has some potential to reduce the moisture of stools from dogs and cats receiving the additive at 5 x 109 CFU/kg feed. However, the biological relevance of the magnitude of the effect detected is questionable.