Chlorhexidine is Superior to Ozonized Water in the Reduction of the Oral Cavity Microbiota of Horses

In equine husbandry, oral cavity procedures are commonly performed and may be associated with complications, including extraoral diseases, potentially resulting from bacterial contamination and inadequate antisepsis. Bacterial resistance to antimicrobials is a major issue for healthcare professionals, including veterinarians that may misuse these pharmaceuticals. Therefore, developing novel methods for antisepsis is desirable. This study aims to test the effectiveness of a 100 µg/ml ozonized injectable water solution versus 0.12% chlorhexidine mouthwash. Fifty adult equines had swab samples collected from their oral cavities, to make cultures and isolate the main microorganisms present. Half of the animals then had their mouths washed with 0.12% chlorhexidine and the other half were treated with the 100 µg/ml ozonized solution mouthwash. Following these treatments, another swab sample was obtained from each animal, and the culture repeated. The number of colony-forming units (CFUs) and the number of times a microbe genus was present were counted. The genera isolated were coagulase-negative <i>Staphylococcus</i>, <i>Klebsiella</i>, <i>Escherichia</i>, <i>Streptococcus</i>, and <i>Pseudomonas</i>, as well as yeast cells. The first 3 were the most prevalent, present in over 70% of the animals. The authors concluded that in healthy horses, a single mouth rinse with a 100 µg/ml ozonized solution was less effective than 0.12% chlorhexidine for reducing CFU count and presence. This study confirmed the known efficacy of chlorhexidine and its superiority to ozonized water. It also highlighted the importance of performing procedures antiseptically.