GERMICIDAL ACTIVITY OF A CHLOROUS ACID CHLORINE DIOXIDE TEAT DIP AND A SODIUM-CHLORITE TEAT DIP DURING EXPERIMENTAL CHALLENGE WITH STAPHYLOCOCCUS-AUREUS AND STREPTOCOCCUS-AGALACTIAE

Three postmilking teat dips were tested for efficacy against Staphyloc occus aureus and Streptococcus agalactiae in two separate studies usin g experimental challenge procedures that were recommended by the Natio nal Mastitis Council. The first study evaluated a barrier teat dip pro duct containing chlorous acid-chlorine dioxide as the germicidal agent , and the second study evaluated a sodium chlorite product with a barr ier component as well as a sodium chlorite product without a barrier c omponent. The chlorous acid-chlorine dioxide teat dip reduced new intr amammary infections (IMI) caused by Staph. aureus by 91.5% and reduced new IMI caused by Strep. agalactiae by 71.7%. The barrier dip contain ing sodium chlorite reduced new IMI caused by Staph. aureus and Strep. agalactiae by 41.0 and 0%, respectively. The nonbarrier dip containin g sodium chlorite reduced new IMI caused by Staph. aureus by 65.6% and reduced new IMI caused by Strep, agalactiae by 39.1%. Teat skin and t eat end conditions were evaluated before and after the second study; n o deleterious effects among dipped quarters compared with control quar ters were noted for the two sodium chlorite products.