# Chlorine Dioxide Teat Disinfectant: A Clinical Study on Bactericidal Efficacy and Safety in Dairy Cows in Comparison with an Iodine Glycerin Disinfectant

## TL;DR

A new chlorine dioxide disinfectant for dairy cows is as safe as traditional iodine-based products and more effective at killing harmful bacteria.

## Contribution

A novel chlorine dioxide teat disinfectant is shown to have superior bactericidal efficacy compared to iodine glycerin with no adverse effects on teat health.

## Key findings

- Chlorine dioxide disinfectant achieved a higher log10 reduction in bacterial counts compared to iodine glycerin.
- Chlorine dioxide completely eradicated all tested pathogens including Staphylococcus aureus, E. coli, and Streptococcus spp.
- Both disinfectants maintained similar teat health metrics with no significant differences in dryness or hyperkeratosis.

## Abstract

Mastitis is a common disease in dairy cows caused by harmful bacteria, leading to eco-nomic losses in the dairy industry. This study compares the effectiveness and safety of two teat disinfectants: a new chlorine dioxide-based disinfectant and the traditional io-dine glycerin disinfectant. The study involved 100 cows in a long-term trial and 40 cows in a teat surface disinfection experiment. The results showed that both disinfectants were equally effective in reducing somatic cell counts and maintaining teat health. However, chlorine dioxide demonstrated a stronger bactericidal effect, completely eradicating harmful bacteria such as Staphylococcus aureus, E. coli, and Streptococcus spp. The findings suggest that chlorine dioxide is a promising alternative to iodine-based disin-fectants, offering similar or even better outcomes while being environmentally friendly and residue-free.

This study evaluated the clinical bactericidal efficacy and safety of a novel chlorine dioxide teat disinfectant compared to a traditional iodine glycerin disinfectant in dairy cows. The randomized controlled trial included long-term natural exposure (100 cows) and teat surface disinfection (40 cows) experiments. Key metrics assessed were somatic cell count (SCC), teat skin health (dryness, roughness, hyperkeratosis), and bacterial reduction rates against Staphylococcus aureus, Escherichia coli, and Streptococcus spp. Results demonstrated that the chlorine dioxide teat disinfectant achieved comparable to iodine glycerin disinfectant in controlling the rate of SCC exceeding the threhold (3.57% vs. 4.50% at day 10; p > 0.05), teat skin dryness, end roughness, and hyperkeratosis severity showed no significant differences over time or between iodine glycerin (control) and chlorine dioxide teat disinfectant groups (all p > 0.05). Notably, quantitative bacteriological assessment revealed significantly higher log10 reduction values for chlorine dioxide teat disinfectant (2.14) versus iodine glycerin controls (1.93; p < 0.05). Microbiological evaluation further demonstrated complete pathogen eradication (100.00%) by chlorine dioxide across all isolates (S. aureus, E. coli, Streptococcus spp.), whereas iodine glycerin achieved 99.84–100.00% bactericidal rates. The findings suggest that chlorine dioxide teat disinfectant is a sustainable and effective alternative to iodine glycerin disinfectant, offering robust antimicrobial activity, improved teat condition, and reduced residue concerns. Further multicenter studies are warranted to validate these outcomes under diverse herd management conditions.