The effect of ozonated sterile saline irrigation on the endometrium – A preliminary study

Safety and Effects of a Commercial Ozone Foam Preparation on Endometrial Environment and Fertility of Mares

Mares' subfertility represents a complex diagnostic and therapeutic challenge and both clinical and subclinical endometritis are considered major causes of impaired fertility. Thanks to its properties, ozone has a big potential as a treatment for equine endometritis. Therefore, the aim of this study is to describe the safety and the effects on endometrium and reproductive parameters of mares of a commercial ozone foam preparation (Riger Spray®). Twenty-four mares were treated during estrus: ozone group with an intrauterine instillation of ozone foam preparation (OG, n=16) and control group with 20 ml of lactated Ringer's solution (CG, n=8). Samples for endometrial cytology were collected before the ozone treatment (T0), after 24 h (T1), after one week (T2), two weeks (T3), and when the subsequent estrous phase was detected (T4). Furthermore, samples for histological examination and uterine swab for bacteriological examination were collected at T0 and T4. At T1, a statistically significant increase of endometrial inflammation in the OG mares compared to T0 (P<.05) and to CG at same time point (P<.05) was observed, but it was already resolved at T2. No differences in endometrial inflammation in CG, biopsy grade before and after the treatment in the two groups, number of mares pregnant at the end of the season and number of mares pregnant at the first cycle were observed. However, the number of inseminations required for pregnancy tended to be lower (P=.0711) in the OG (1.69±0.06) than in CG mares (2.60±0.89).

Endometrial angiogenesis induced by uterine insufflation with an oxygen-ozone gas mixture in mares

Ozone (O₃ ) therapy has been used to improve peripheral tissue oxygenation in humans and domestic animals. The goal of the present study was to characterize histological changes in the endometria of healthy equines following tissue exposure to gas mixtures enriched with different concentrations of O₃ . Cycling mares without endometrial degeneration were divided into three groups according to treatment (n = 9 mares/group). The uteri from the O₃ , ½O₃ and control groups were insufflated for 3 min with gas containing 42, 21 and 0 μg O₃ ml^-1 , respectively. Treatments were performed every three days from D0 to D6. Endometrial samples were collected immediately before the first treatment and 24 hr after the last treatment. The following nine histological parameters were evaluated: (i) the number of endometrial blood vessels, (ii) endometrial vascular degree (EVD), (iii) increase rate of blood vessels, (iv) increase rate of EVD, (v) glandular total area, (vi) glandular lumen area, (vii) intraglandular secretion area, (viii) glandular epithelial height and (ix) luminal epithelial height. In the O₃ group, a positive effect from treatment (p < .01) was detected for all vascular parameters (i, ii, iii and iv), glandular total area, intraglandular secretion area and glandular epithelial height. Compared to the control group, the ½O₃ group had greater (p < .01) EVD (84.1 ± 12%) and a higher increase rate of blood vessels (151.9 ± 47.1%). Uterine insufflation with low or intermediate concentrations of the O₂ -O₃ gas mixture induced endometrial angiogenesis. Morphometry, but not morphology, of the endometrial glands was affected by local O₃ therapy. These findings would be of great significance for the development of new therapies for infertility in mares.

Intrauterine therapy with ozone reduces subclinical endometritis and improves reproductive performance in postpartum dairy cows managed in pasture-based systems

New postpartum strategies have been developed in dairy cows to ameliorate uterine health and reproductive performance, especially the first service conception rates. This study aimed to assess the effect of intrauterine therapy with ozone (IUTO) in early postpartum on subclinical endometritis prevalence and reproductive parameters in dairy cows under commercial farm conditions. For this purpose, eighty clinically healthy cows with a body condition score between 3.0 and 3.5, from four dairy farms, were randomly allocated into two groups: ozone therapy group (OG, n = 40), which were subjected to IUTO, and control group (CG, n = 40). Content of uterine polymorphonuclear (PMN) leukocytes and subclinical endometritis (SE) percentage were assessed at 35 days after calving by uterine cytology. A second cytology was performed 72 h after IUTO. Reproductive parameters such as interval calving to first service (IFS), number of services per conception (nSC), interval calving to conception (ICC) and first service conception rate (FSCR) were analysed. The second endometrial cytology demonstrated that IUTO reduced (P < 0.01) both PMN (3.7 ± 1.4 vs. 7.6 ± 1.1%) and SE (5.0 vs. 50.0%) percentages compared with CG. Likewise, after ozone treatment, both nSC (2.1 ± 0.3 vs. 3.1 ± 0.2; P < 0.01) and ICC (126.2 ± 9.7 vs. 149.0 ± 9.0; P = 0.0672) decreased, and FSCR increased (50.0 vs. 16.2%; P < 0.01) compared with CG. In conclusion, intrauterine ozone therapy applied at 35 days after calving reduced subclinical endometritis prevalence and improved reproductive performance in postpartum dairy cows managed in a pasture-based system.