A Modified One-Stage Repair of Third-Degree Rectovestibular Lacerations in Mares

A modified one-stage surgical repair was performed on eight mares that suffered from third-degree rectovestibular lacerations. The rectovestibular septum was reconstructed by three lines of sutures using polydioxanone. Primary healing was achieved in seven mares. Four mares got pregnant after the surgery, and no further injury was noticed at subsequent delivery. Complications of the currently used technique included pneumorectum (in one mare) and rectovestibular fistula (in another mare). The obtained results indicated that mares with third-degree rectovestibular lacerations are candidates for this modified one-stage technique with satisfactory outcome for subsequent fertility.     

Consequences of Intrauterine Enrofloxacin Infusion on Mare Endometrium

Endometritis is an important cause of infertility in mares. Enrofloxacin is a broad-spectrum antibiotic to which most equine endometritis pathogens are not resistant. The objective of this study was to determine whether enrofloxacin is safe to use as a conventional intrauterine infusion treatment. Nine healthy mares received intrauterine infusions of enrofloxacin (Baytril 100, 100 mg/mL, Bayer Health Care LLC, Animal Health Division) at 2.5 mg/kg daily for 3 days. Ultrasonographic examination and vaginal examinations were performed during the study. Endometrial biopsies were performed before treatment (S0) and 24 hours after the last treatment (S1) to evaluate acute effects. For evaluating chronic effects, biopsies were performed at 14 days (S2) and 60 days posttreatment (S3). Biopsies were graded histologically by the Kenny and Doig category scale. Difference in histological biopsy grade before and after treatment was compared between biopsies by using a repeated-measures one-way analysis of variance. and significant changes in grades were used to assess treatment effects. The vaginal and ultrasonographic examination after intrauterine infusion of enrofloxacin showed that all mares had severe purulent vaginitis and uterine fluid accumulation of ≥2 cm, with ≥1.5-cm thickening of the endometrial wall which persisted in most mares until the end of the study. Histologically, there was acute endometrial ulceration, necrosis, and hemorrhage in biopsy S1 in all mares, categorized as grade III. In biopsy S2, most mares developed fibrosis and inflammation graded as IIb (four of nine mares) or III (four of nine mares). In biopsy S3, fibrosis was extensive and had variable inflammation, graded as IIb (two of nine mares) or III (five of nine mares), with some mares healing to grade IIa (two of nine mares). There was an overall worsening of endometrial biopsy grade from I to III at S3 compared with S0 (P < .001). These results confirm that enrofloxacin is not suitable for conventional intrauterine infusion treatment in mares.     

Surgical management of perineal lacerations and rectovestibular fistulae in the mare: a retrospective study of 47 cases

The case records of 47 mares with third-degree perineal lacerations or rectovestibular fistulae were examined to evaluate their fertility following surgical repair. Of 32 mares bred, 24 became pregnant, suggesting that surgical repair is indicated in any mare with sufficient genetic potential. Perineal trauma after surgical repair was recorded in 3 of 20 mares at subsequent parturition.     

Comparison of Clinical Signs,Endometrial Culture,Endometrial Cytology,Uterine Low-Volume Lavage,and Uterine Biopsy and Combinations in the Diagnosis of Equine Endometritis

Endometritis is the most common cause of infertility in mares; however, many mares fail to be diagnosed despite availability of many diagnostic tests. Our objective was to compare different diagnostic methods and establish a cutoff value for the number of polymorphonuclear cells in cytology samples. Fifty-four mares were classified positive for endometritis based on endometrial biopsy (“gold standard”), and in a later analysis, the mare was reclassified as positive for endometritis if two or more of the following five criteria on a checklist were present (“new gold standard” [NGS]): (1) abnormal clinical findings, (2) abnormal gross character of low-volume lavage (LVL) fluid, (3) positive endometrial cytology, (4) bacterial growth on culture of the LVL pellet, and (5) histologic evidence of inflammation on endometrial biopsy. Kappa (κ) coefficient and percentages were calculated for sensitivity and positive predictive value (PPV) using SAS 9.3 software. Endometritis was diagnosed in 35/44 (79.5%) mares by biopsy. Based on the endometritis checklist, 33/51 (64.7%) mares were positive for endometritis. The character of LVL was 45% sensitive, whereas culture was 22% sensitive, when compared with endometrial biopsy. One percent of neutrophil-to-epithelial cell ratio was the most sensitive cutoff value (93.3%) when using a guarded swab (κ = 0.64). Endometrial biopsy was the most sensitive diagnostic method when compared against the NGS (sensitivity = 86%). Abnormal clinical findings and positive cytology showed moderate agreement with the NGS (κ = 0.41 and κ = 0.38, respectively). These studies demonstrate the importance of combining clinical findings and laboratory data when evaluating mares for endometritis.     

Morphologic evaluation of acute endometritis in mares with differing resistance to uterine infections

The study was designed to determine differences between normal mares and mares with endometrial pathology in the inflammatory response after bacterial challenge. Six normal mares (biopsy category I) and 4 mares with pathological endometrial changes (biopsy category II) were given an intrauterine infusion of β-hemolytic streptococci on the second day of estrus. All mares had a similar kind of inflammatory response after the bacterial inoculation as assessed by rectal and vaginal examinations. There were no significant differences in the amount of discharge, uterine tone, uterine size and cervical relaxation between the groups. Leukocytic response, as determined by endometrial smears and biopsies, was of the same magnitude in both groups. Two mares from the pathological group were not able to eliminate the infection, but had vaginal discharge and bacteriologically positive uterine swabs until the end of the experiment. It is concluded that the inability of some mares to clear uterine infections cannot be explained by a deficient inflammatory response.     

The Effects of Treatment with N-Acetyl Cysteine on Clinical Signs in Persistent Breeding-Induced Endometritis Susceptible Mares

Persistent breeding-induced endometritis (PBIE) is a major cause of infertility in mares. Endometrial inflammation that persists until embryonic descent ultimately results in early embryonic death. A poor endometrial biopsy grade (IIb or III) has been identified as a risk factor for PBIE. Intrauterine fluid accumulation (>2 cm in depth), pathologic endometrial edema, and elevated intrauterine neutrophil levels are all clinical features of PBIE. Commonly applied treatment options include uterine lavage and oxytocin therapy. N-acetyl cysteine (NAC), a mucolytic used to treat bacterial endometritis in mares, has anti-inflammatory properties and was investigated as a potential treatment for PBIE. A randomized, blinded, cross-over design clinical trial used NAC before breeding in PBIE-susceptible mares (n = 9). Intrauterine infusion of 3.3% NAC was performed 12 hours before insemination, and endometrial cytology and endometrial biopsy samples were obtained at 12 and 60 hours after insemination. Endometrial biopsies were evaluated for the degree of inflammation present. Clinical signs of endometrial edema and intrauterine fluid volumes were assessed by transrectal ultrasound at 12 and then every 24 hours after breeding. Data were analyzed using repeated measures analysis of variance and a Mann Whitney Wilcoxon Test. Treatment with NAC did not improve clinical signs in PBIE-affected mares. However, endometrial biopsies from mares treated with NAC displayed more diffuse and severe neutrophil infiltration than control cycles. Further research using a larger population of mares is required to evaluate the effects of NAC treatment on the endometrium of PBIE-susceptible mares.     

A modified surgical technique for repairing third-degree perineal lacerations in mares

A modified surgical technique has been developed for repairing third-degree perineal lacerations in mares. Complications of the currently used methods include rectovaginal fistula formation, urine pooling, complete dehiscence of the repair, constipation, tenesmus and difficulty of performance in the practice. The modified method is simpler and more practical. This method was performed on eight Thoroughbred mares with third-degree perineal lacerations after delivery. The rectovestibular septum was reconstructed by three lines of sutures in a transverse direction in relation to the longitudinal axis of the rectum. In one of the eight cases pneumorectum was observed after using the new method. The conception rate obtained after using the new surgical technique was 62.5%. Pregnant mares delivered normally without any new lacerations at the subsequent parturition. It can be concluded that this new surgical technique can be used successfully for repairing third-degree perineal lacerations in mares.     

Endometritis in the mare caused by a Coryneform organism--a case report and experimental studies

Persistent purulent endometritis in a mare was attributed to an unclassified species of Corynebacterium. Following intrauterine infusions of 20% betadine for 5 days the purulent vulval discharge ceased and the mare appeared clinically normal. Based on histological examination of endometrial biopsy samples, the severe acute inflammatory reaction had largely resolved 2 days after therapy. Three maiden mares considered resistant to bacterial endometritis received single intrauterine inoculations of 1.8 X 10(9) colony-forming units of the Corynebacterium species. The uterine response was followed by vaginal speculum examinations, uterine cultures and cytology, and endometrial histology. After an acute inflammatory reaction, each mare had recovered completely within 2 weeks. Most rapid recovery occurred in the mare in estrus at the time of inoculation. Subsequent secondary infections were detected in two mares. The uncertainty of correlations between results obtained by various diagnostic techniques emphasized the problems associated with each. This report illustrates the concept that endometritis in individual mares may relate more to as yet unidentified "mare factors" controlling uterine defense than to primary invasion by bacteria.     

Effect of repeated collection of multiple endometrial biopsy specimens on subsequent pregnancy in mares.

Endometrial biopsy specimens (4 or 5 on each occasion) were collected from 7 mares 2, 3, or 4 times over a 50-day period prior to breeding. Four of the collection days were within 6 days of breeding. Six of the 7 mares were diagnosed as pregnant by use of ultrasonography at day 14 after ovulation. This pregnancy rate was the same as that achieved by these mares when they were bred at estrus before the start of the study. It appeared that repeated collection of multiple endometrial biopsy specimens from genitally normal mares did not adversely affect pregnancy rate.     

Endometritis in she donkeys in Egypt

The endometrial necropsies of 165 she donkeys were examined and the endometria were classified into four grades according to histological features (I, IIa, IIb, III). Category I was observed in 86 cases (52.12%) and diagnosed as normal endometria. Category IIa was observed in 18 cases (10.91%) and diagnosed as slight endometritis. Category IIb was observed in 28 cases (16.97%) and diagnosed as moderate endometritis (two to four nests/field), while category III was observed in 33 cases (20%) and diagnosed as severe endometritis (eight nests/field). A bacteriological examination was carried out and oestrogen and progesterone were estimated. Our results indicate that endometritis and the prognosis of fertility in she donkeys were more or less parallel to mares.     

The effect of age and parity on the development of equine chronic endometrial disease

The results of a retrospective analysis of 3,804 endometrial biopsy specimens collected from non-pregnant mares during the course of routine equine stud farm practice demonstrates a significant and practically useful correlation between the severity of chronic degenerative endometrial disease (CDE) diagnosed and age of mare at the time of examination. There were significant correlations between the number of foals born and the mares' barren years prior to biopsy and the severity of CDE, but the differences were not sufficiently large to be useful. Correlations between the severity of chronic infiltrative endometritis (CIE) and age or pre-biopsy parity were minimal. The results suggest that using similar histopathological criteria to those used by Kenney and Doig (1986), mares up to nine years of age should have no signs of CDE, mares up to 13 years of age should have no more than mild signs, mares up to 15 years of age should have no more than moderate signs and mares aged 17 years or older are likely to have severe signs. We believe that these guidelines are a useful, objective aid for formulating a breeding prognosis.     

Effect of a povidone-iodine intrauterine infusion on progesterone levels and endometrial steroid receptor expression in mares

Background

Intrauterine infusions have been widely used for the treatment of endometritis in the mare. Nevertheless, their consequences on endocrine and endometrial molecular aspects are unknown. We studied the effect of a 1% povidone-iodine solution intrauterine infusion on progesterone levels, endometrial histology and estrogen (ERα) and progesterone (PR) receptor distribution by immunohistochemistry.

Methods

Fourteen healthy mares were used in this study. Estruses were synchronized and seven mares were treated with intrauterine infusions at days 0 and 2 post ovulation of two consecutive estrous cycles. Uterine biopsy samples were taken on days 6 and 15 post ovulation.

Results

The treatment did not induce an inflammatory response indicating endometritis, neither affected the ERα. However, it reduced the percentage of PR positive cells (PPC) on day 6 (deep glandular epithelium, control: 95.7 vs. infused: 61.5, P < 0.05). Treated mares tended to have lower progesterone levels on day 2 (3.9 ng/ml vs. 6.6 ng/ml, P = 0.07), and higher levels on day 15 compared with controls (4.4 ng/ml vs. 1.3 ng/ml, P = 0.07).

Conclusion

a 1% povidone-iodine infusion during days 0 and 2 post ovulation in healthy mares did not induce histological changes indicating endometritis, but altered progesterone concentrations and reduced the expression of endometrial PR at day 6 without affecting the ERα. These changes could reduce embryo survival.     

Efficacy of intrauterine infusion of plasma for treatment of infertility and endometritis in mares

We evaluated the efficacy of intrauterine plasma infusion in mares as a treatment for infertility caused by endometritis and distinguished the effects of intrauterine infusion of plasma vs saline solution. Forty-three subfertile mares were randomly assigned to 1 of 3 treatment groups: untreated controls (n = 14), those treated by saline infusion (n = 14), and those treated by plasma infusion (n = 15). Reproductive status was assessed daily by transrectal ultrasonography. Uterine aspirates and biopsy specimens were obtained 8 days after ovulation for cytologic and histologic evaluation, and mares were treated on days 12 to 16. Uterine aspirates and biopsy specimens were obtained again on day 8 of the next estrous cycle, and the mares were bred at the subsequent estrus. A postovulation intrauterine infusion of either plasma or saline solution was administered to mares in their respective treatment groups. Biopsy specimens were scored from 1 (no indications of inflammation) to 6 (severe inflammation). The pregnancy rate was lower (P less than 0.005) for mares with scores 5 and 6 (0/5) than for those with scores 1 to 4 (17/35). There was no significant effect of treatment nor a treatment by biopsy score interaction on pregnancy rate; however, the pregnancy rate for mares treated with plasma or saline solution (9/27) tended to be lower than for the control (untreated) mares (8/13). There was no change in mean biopsy score between specimens obtained before treatment and those obtained after treatment for the control group and the group treated with saline solution; however, there was a significant increase (P less than 0.05) in scores in the group treated with plasma.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative histomorphological study of endometrium in mares

Uterine acute post‐breeding inflammation is a physiological tissue response to the entry of exogenous elements, with persistent endometritis being the main pathology responsible for subfertility in the mare (Equus ferus caballus; Linnaeus, 1758). Mares can be classified as susceptible or resistant to endometritis according to their ability to remove intrauterine fluid within 48 hr after experimental inoculation. Endometrial biopsy is a technique that is commonly used to establish the degree of lesions that can affect the fertility of the mare. Endometrial histomorphometry is an objective and highly precise diagnostic method. The aim of this study was to compare, during oestrus, the endometrial histomorphometry of mares previously classified as susceptible (SM) or resistant (RM) to endometritis. Endometrial biopsies from 24 mares at the oestrus phase of the cycle were obtained. For the histomorphometric analysis, samples were histologically processed and subjected to routine Haematoxylin–Eosin staining. For the evaluation, the variables were considered as follows: 1‐Height of the lining and glandular epithelia (Lining SM = 15.9 μm vs. RM = 13.3 μm; Glandular SM = 15.0 μm vs. RM = 13.0 μm); 2‐Perpendicular diameters of endometrial glands (SM = 51.3 μm vs. RM = 44.8 μm); 3‐Number of endometrial glands per field (SM = 24.8 glands/field vs. RM = 20.5 glands/field). The results from this study suggest the existence of a relationship between the studied characteristics and the susceptibility/resistance to post‐breeding endometritis in mares. Thus, increased epithelial height, greater glandular density and greater development of the glands during oestrus would be related to a higher susceptibility to endometritis.     

Plasma concentrations of 13,14-dihydro-15-ketoprostaglandin F2 alpha in mares during uterine involution.

Twelve mares were allowed to foal naturally, after which they were monitored to study uterine involution. Starting on day 3 after parturition, the internal genital tract was examined per rectum manually and ultrasonographically every other day for changes in uterine characteristics and ovarian activity. By day 5, gravid and nongravid uterine horns were similar in size, and by day 7, uterine fluid was absent. On day 7 after parturition, endometrial biopsy samples were obtained for histologic evaluation, and uterine swab specimens were obtained for microbiologic culture. Uterine swab specimens from 10 of 12 mares had slight bacterial growth. The uteri of 8 of the 12 mares were histologically involuted by day 7. All mares ovulated 7 to 12 days after parturition. Concentrations of 13,14-dihydro-15-keto-PGF2 alpha (PGFM) were measured in jugular plasma samples obtained daily for 21 days after parturition. Concentrations of PGFM were low by the day after parturition, and there was no significant correlation between uterine involution and PGFM concentrations in these mares. All 12 mares were bred at the first estrus after parturition, and 9 became pregnant.     

Third-degree perineal lacerations and rectovestibular fistulae in cattle: 20 cases (1981-1988)

The case records of 20 cows with either a third-degree perineal laceration or rectovestibular fistula were reviewed to ascertain the signalment, history, treatment, and long-term result of treatment. Fifteen cows, including 10 first-calf cows, had third-degree perineal lacerations that occurred at calving. Surgery was done in 14 of 15 cows; 10 of the 14 (71%) remained fertile. The cow that was not treated surgically was culled after 24 months because of infertility. Five cows had a rectovestibular fistula; 4 of these were treated surgically. The cow that did not have surgery healed by second intention and remained fertile, and 3 of the 4 cows in which surgery was performed were fertile. None of the cows that produced calves after the initial injury suffered a perineal laceration at subsequent calvings. Single-stage surgical repair of third-degree perineal laceration or rectovestibular fistula appeared to have a good prognosis for subsequent fertility in cows.     

Feasibility and Safety of Endometrial Injection of Autologous Bone Marrow Mesenchymal Stem Cells in Mares

​Chronic degenerative endometritis (CDE) is an important cause of fertility problems in older mares. It is estimated that 30% of mares breeding are over 18 years old and the high value of their progeny encourages the use of these animals in assisted reproduction procedures. Currently, cell-based therapies are broadly used in human and veterinary regenerative medicine and have been showed a good effect on the treatment of liver fibrosis. Thus, the present study aimed to evaluate the feasibility and safety of endometrial injection of autologous bone marrow MSCs in mares. Mares were examined by transrectal ultrasound and the endometrial stem cells injections performed during diestrous, using injection needles coupled to a teflon catheter through the biopsy channel of a flexible endoscope. After treatment clinical evaluations (heart reat, respiratory rate, staining of the mucosa, capillary refill time, body temperature and lameness score) were performed daily during seven days. The intrauterine fluid and endometrial edema was evaluated before, 24 and 48 hours after the procedure by ultrasonographic exams and the inflammatory infiltrate (polymorphonuclear cells and mononuclear cells) and degree of fibrosis by histological evaluations before (D0) and 15 (D15), 30 (D30) and 60 (D60) days after endometrial injections. The results were evaluated by Kolmogorov-Smirnov and Kruskal-Wallis test followed by Dunn test and for fertility rates was used Chi-square, considering a 5% significance level. Neither clinical alteration was observed in mares after treatment, as well as, intrauterine fluid and endometrial edema were not detected in any mare before and after cell therapy. After cell therapy, significantly more PMNs were found in D15 biopsies, however, these cells were not observed in D30 and D60 biopsies. No worsening on the histological architecture after treatment was observed in any mare. In conclusion, the results of this study showed that endometrial hysteroscopic injections of stem cells in mares is a safe procedure.     

The Use of Endometrial Biopsy in the Infertile Mare

The results of a study on endometrial biopsies obtained from 700 infertile mares are reported. Infiltrative endometritis was present in 51% consisting of a combination of an acute and chronic cellular response in 6%, mild chronic infiltrations in 35% and moderate to severe chronic infiltrations in 10%.

Demonstrable endometrial fibrosis was found in 88% of the mares with the majority having mild (51%) or moderate (35%) changes. The age of the mares and the average number of years barren gradually increased with the severity of endometrial fibrosis, as did the combined incidence of fetal loss (early embryonic death and abortion) during the three year period preceding the biopsy.

A significant decrease in foaling percentage for the year following the biopsy was observed with increasing severity of endometrial fibrosis. Chisquare analysis projected a decrease in foaling rate of 22.8% for each category increase in severity.

The number of years barren and the farm management system used also had a significant effect on foaling probability. The foaling rates for mares that were bred artificially (82%) under strict veterinary supervision using an extender incorporating gentamicin were significantly (P < 0.05) higher than for mares bred in a conventional manner under average management conditions (48%).

It was concluded that endometrial biopsy is a valuable diagnostic and prognostic technique. When the degree of fibrosis is used to predict foaling probability, the number of years barren and the breeding method to be used should also be considered to arrive at a more accurate prediction.

     

Use of a Mycobacterial Cell Wall Extract (MCWE) in Susceptible Mares to Clear Experimentally Induced Endometritis With Streptococcus zooepidemicus

The ability of an immunomodulator, mycobacterial cell wall extract (MCWE), to clear uterine infection in susceptible mares after an experimental challenge withStreptococcus zooepidemicus was evaluated. Thirty mares susceptible to endometritis, based on the presence of uterine fluid during both diestrus and estrus, were selected from a herd of 896 and inoculated with a live culture of 5 × 10⁶ CFU of S. zooepidemicus on day 1 of estrus. Twenty-four hours later, mares were evaluated by ultrasonography, bacteriology, exfoliative cytology, and uterine biopsy to confirm infection. Forty-eight hours after inoculation, and on confirmation of uterine infection, mares were randomly assigned to one of four unbalanced experimental treatments to receive 1500 μg MCWE IU (n = 10) or IV (n = 10), or placebo IU (n = 5) or IV (n = 5). Mares were examined at ovulation and 7 days post-ovulation for uterine fluid via transrectal ultrasonography and for bacteriology, exfoliative cytology, and uterine biopsy. Efficacy was based on the ability of the mare to clear endometritis as determined by negative bacteriology and reduced numbers of polymorphonuclear cells (PMNs) on uterine biopsy. Because no statistical difference was detected between routes of administration on day 7 post-ovulation, the data sets were combined and re-analyzed to evaluate overall efficacy. Endometritis was observed in all placebo-treated mares 7 days post-ovulation, whereas treatment with MCWE resulted in the elimination of endometritis in 35% of the mares by the time of ovulation, and 70% of the mares by 7 days post-ovulation. Treatment with MCWE, compared with the placebo group, resulted in a significant decrease in the number of mares positive for endometritis at ovulation based on exfoliative cytology and bacteriology (P < .01) and at 7 days post-ovulation based on biopsy, exfoliative cytology, and bacteriology (P < .001). Results indicate that MCWE was an effective treatment for the elimination of endometritis caused by S. zooepidemicus in mares.     

The technique and clinical application of endometrial cytology in mares

Experimental studies of endometrial smears from 26 normal mares showed that after a period of sexual rest exceeding 7 days smears were generally free from inflammatory cells. Smears from 9 mares showing signs of persistent endometritis contained inflammatory cells in 91 per cent while bacterial culture was positive in only 45 per cent. Smears were also taken from 242 Thoroughbred mares as a routine procedure in 1977. It was concluded that endometrial cytology provides a better guide to uterine inflammation than bacteriology. The routine clinical use of endometrial cytology is recommended to aid the interpretation of both positive and negative bacterial cultures from the cervix.