Ozone therapy in the treatment of endometritis in mares

This sounds very promising for chronic endometritis treatment. Now we need some pregnancy rate numbers to verify the improved breeding environment.
DrO

Effectiveness of ozone therapy in the treatment of endometritis in mares
J Equine Vet Sci. 2022 Feb 17;103900. doi: 10.1016/j.jevs.2022.103900. Online ahead of print.
Authors
Ana Caroline Araújo Ávila 1 , Natália Castro Diniz 1 , Rafael Torres Serpa 1 , Maria Manoela Barata de Castro Chaves 1 , Marco Antônio de Oliveira Viu 2 , Rodrigo Arruda de Oliveira 3
Affiliations

1 Faculty of Veterinary Medicine, Laboratory of Animal Reproduction, University of Brasília (FAV/UnB), Brasília, DF.
2 Faculty of Veterinary Medicine, UFG, Jataí, GO.
3 Faculty of Veterinary Medicine, Laboratory of Animal Reproduction, University of Brasília (FAV/UnB), Brasília, DF. Electronic address: rodrigoarruda@unb.br.

Introduction
Intrauterine treatment with O3 therapy has been shown to be effective in reducing uterine inflammation in cows [13] as well as in local promotion of endometrial angiogenesis without inducing tissue damage in mares [11]. Moreover, O3 therapy has an antimicrobial effect [14,15]. O3 gas activates erythrocyte metabolism and immune cells [16] and shows the ability to react with many compounds, such as phospholipids, lipoproteins, bacterial cell envelopes, and viral capsids [17]. The anti-inflammatory and bactericidal effects of ozonated oils have been demonstrated both in vitro and in vivo [15,18,19,20,21]. Therefore, this study aimed to evaluate the effectiveness of treatment using two O3 presentations (O2-O3 gas mixture and ozonized sunflower oil) in comparison with conventional control treatment for endometritis.

Endometritis is defined as inflammation of the endometrium that may be acute or chronic, infectious, or non-infectious. Endometritis is an important cause of subfertility in mares. Considering the antimicrobial characteristics, immune-stimulating ability, and low cost of ozone (O3) therapy, we aimed to evaluate the effectiveness of intrauterine O3 therapy as an alternative treatment for endometritis in mares. Twenty-five mares with a known reproductive history of uterine infection and inflammation were allocated into three groups: Group 1 (control; n = 7), uterine lavage with Ringer’s lactate solution; Group 2 (O3-gas; n = 9), uterine lavage with Ringer’s lactate solution followed by uterine insufflation with O2-O3 gas mixture containing 40 µg O3 mL−1 for 10 minute; and Group 3 (O3-oil; n = 9), uterine infusion of ozonized sunflower oil. Uterine inflammation was evaluated through a uterine cytological examination (cytobrush) and uterine culture (swab) for microbiological content before and after all treatments. In assessments of uterine cytology, the average number of neutrophils/field changed from 9.14 ± 3.02 to 7.71 ± 3.59 in the control group, from 10.67 ± 3.84 to 2.89 ± 3.59 in the O3-gas group, and from 6.44 ± 2.79 to 6.55 ± 7.18 in the O3-oil group post-treatment. The pre- and post-treatment findings in the mares treated with ozonized gas were significantly different (P < .05), unlike the findings for the mares in the control and O3-oil groups. All mares (25/25) showed a positive uterine culture before treatment. After treatment, the percentage of mares showing positive culture results was 57%, 11%, and 22% in the control, O3-gas, and O3-oil groups, respectively. Our results showed the effectiveness of two groups (O2-O3 gas mixture and ozonized sunflower oil) for the treatment of uterine infections in mares. Conclusion Under the experimental conditions described in this study, direct infusion of O3-gas in association with uterine lavage proved to be effective in controlling uterine infection and inflammation. Due to its antimicrobial activity, O3 may be useful in preventing the spread of antibiotic-resistant bacteria and antibiotic resistance genes.