Efficacy evaluations on five chlorhexidine teat dip formulations

Area of Science:

• Veterinary Medicine
• Microbiology
• Animal Health

Background:

• Bovine mastitis remains a significant economic challenge in the dairy industry.
• Effective postmilking teat disinfection is crucial for controlling intramammary infections (IMI).
• Chlorhexidine digluconate is a common antimicrobial agent used in teat dips.

Purpose of the Study:

• To evaluate the efficacy of developmental and commercial chlorhexidine digluconate teat dips against Staphylococcus aureus and Streptococcus agalactiae.
• To assess the performance of these teat dips under both experimental and natural exposure conditions.

Main Methods:

• Three developmental chlorhexidine digluconate teat dip formulations were tested in sequential experimental exposure trials.
• Two commercial chlorhexidine digluconate teat dips were evaluated in natural exposure trials.
• Efficacy was determined by monitoring the incidence of new intramammary infections (IMI).

Main Results:

• Developmental formulations were effective against Staphylococcus aureus but not Streptococcus agalactiae in experimental trials.
• Conventional germicides did not effectively reduce new Streptococcus agalactiae IMI under experimental conditions.
• In natural exposure trials, a 0.35% chlorhexidine dip showed 88.7% efficacy against Staphylococcus aureus and 51.4% against Streptococcus agalactiae. A 0.5% chlorhexidine product demonstrated 86% efficacy against Staphylococcus aureus and 56% against Streptococcus agalactiae.

Conclusions:

• Chlorhexidine digluconate teat dips show potential for controlling Staphylococcus aureus mastitis.
• Further research is needed to improve efficacy against Streptococcus agalactiae.
• Commercial chlorhexidine teat sanitizers demonstrated significant reductions in IMI caused by both pathogens in natural settings.