A clinical approach to determine false positive findings of clinical endometritis by vaginoscopy by the use of uterine bacteriology and cytology in dairy cows

Clinical endometritis in dairy cows is defined as mucopurulent or purulent vulvar discharge 21 days or more after parturition. The diagnosis of clinical endometritis is commonly based on vaginal examination. Techniques to reduce the proportions of false negative findings have been described. This paper discusses a clinical approach to determine the proportion of false positive findings that might occur by vaginal inspection. The consequences of false positive findings in dairy practice are unnecessary or inadequate treatments. In research, incorrect diagnoses have an impact on the interpretation of studies on the diagnosis and treatment of clinical endometritis. The objective of the present study was to compare intrauterine bacteriology and endometrial cytology in cows diagnosed with clinical endometritis with findings obtained by vaginoscopy. Clinical endometritis was defined as mucopurulent or purulent vulvar discharge. On two commercial dairy farms, cows were examined 21 to 28 d postpartum. Uterine samples (n = 230) were collected from cows with clinical endometritis with the cytobrush technique to determine the proportion of polymorphonuclear neutrophils (PMN) and to culture smears for aerobic bacteria. Two threshold values for the proportion of PMN (5 and 18%) were chosen as possible indicators for an inflamed endometrium. Common uterine pathogens A. pyogenes and E. coli were found in 33.5 and 10.4% of the samples, respectively. With increasing vaginal discharge score, proportion of samples positive for A. pyogenes increased significantly. The proportion of cows exceeding the thresholds for PMN increased with vaginal discharge score and the presence of A. pyogenes.Considering only the presence of aerobic uterine pathogens and a proportion of PMN above the threshold values of 5 and 18% as indicative for endometritis, a proportion of 17.3 and 28.5%, respectively, of diagnoses by vaginoscopy were false positive.     

Proinflammatory cytokine gene expression in endometrial cytobrush samples harvested from cows with and without subclinical endometritis

Thirty postpartum cows (28 to 41 days in milk) without signs of clinical endometritis were categorized as inflammation-negative (N = 18) or subclinical endometritis-positive (N = 12) based on endometrial cytobrush cytology (> 18% polymorphonuclear cells; PMNs). Slides for cytology were prepared before the same cytobrush was transferred to a tube containing 1 mL Trizol reagent. Total RNA was extracted from each cytobrush sample and analysis of il6, il8, tnfα, and βactin gene expression was performed using quantitative real-time polymerase chain reaction. Cytobrush sampling provided sufficient material to prepare cytosmears and extract high quality endometrial mRNA (mean = 0.96 μg RNA per sample). Cytokine expression varied between experimental groups with a 20-fold higher tnfα (P = 0.001), a 30-fold higher il6 (P = 0.01), and a greater than 50-fold higher il8 mRNA expression level (P = 0.0001) in subclinical endometritis-positive versus disease-negative cows. Regression analysis of gene expression levels (cycle threshold) versus PMN frequency showed that the frequency of PMNs in the cytosmear decreased by 3.3% (P = 0.000 01), 2.3% (P = 0.015), and 2.4% (P = 0.05) for each additional cycle threshold required to detect il8, il6, and tnfα gene expression, respectively. Expression of the individual cytokines was positively associated: il8 and il6 (P = 0.0001); il8 and tnfα (P = 0.000 01); and il6 and tnfα (P = 0.0002). In conclusion, the endometrial cytobrush technique was successfully used to obtain material for both cytology and RNA extraction, and il8 gene expression may be useful to predict endometrial inflammation.     

Endometrial cytology and ultrasonography for the detection of subclinical endometritis in postpartum dairy cows

The objectives of the study were to validate the use of endometrial cytology (EC) and ultrasonography (US) to diagnose subclinical endometritis in clinically normal postpartum dairy cows, and to measure the impact of subclinical endometritis on reproductive performance. Holstein cows from two dairy farms were examined at Visit 1 (V1) at 20-33 days in milk (DIM), and clinically normal cows (n = 228), based on the absence of abnormal discharge on external inspection and vaginoscopy, were selected. The reproductive tract of selected cows was evaluated by transrectal palpation, US and EC. All cows in the study were re-examined at Visit 2 (V2) at 34-47 DIM (2 weeks after V1) and were subsequently followed for a minimum of 8 months (until pregnant or culled). Survival analysis was used to derive a case definition of subclinical endometritis, based on factors associated with decreased relative pregnancy rate. Positive EC at V1 (>18% polymorphonuclear leukocytes; PMN) or fluid in uterus at V1 (FIU1) were associated with a significant reduction in the relative pregnancy rate and identified cows with subclinical endometritis. Similarly, a positive EC (>10% PMN) at V2 or fluid in the uterus at V2 (FIU2), identified cows with subclinical endometritis. Cows with subclinical endometritis at V1 and at V2 had a relative pregnancy rate of 41 and 51% (hazard ratio for pregnancy of 0.59 and 0.49), respectively, compared to cows without subclinical endometritis. Given EC or US findings, no diagnostic criteria based on transrectal palpation of the uterus had predictive value for risk of pregnancy. In conclusion, subclinical endometritis, diagnosed by EC or US, was associated with reduced relative pregnancy rate.     

Association between endometritis diagnosis using a novel intravaginal device and reproductive performance in dairy cattle

Endometritis reduces reproductive performance in dairy cattle. Diagnosis of endometritis is undertaken using a variety of techniques including vaginoscopy, manual examination, cytology and ultrasonography. The current studies compared a novel test device ("metricheck") that is inserted into the vagina with vaginoscopy and then examined the relationship between the metricheck test score at 35 days before the start of the seasonal breeding programme and subsequent reproductive performance. Cows (n = 191; Study 1) with a history of a peripartum disease were examined by both vaginoscopy and the metricheck device and any material viewed within the vagina (using vaginoscopy) or retrieved (by the metricheck device) was scored on a 0 (no material) to 5 (grossly purulent and with an odour) scale. Within each herd the order of examination was randomized with sequentially presented pairs of cows. All cows (n = 2793; Study 2) from nine herds were examined and scored using the metricheck device 35 days before the start of the seasonal breeding programme. All cows were pregnancy tested to determine date of conception. In Study 1, more cows were defined as infected (i.e. score > 1) following metricheck than vaginoscopic examination (60% versus 43%, respectively; P < 0.05) and the level of agreement between the two tests was moderate (kappa = 0.45). The metricheck device had a higher sensitivity, but lower specificity, than vaginoscopy. Endometritis (i.e. score > 1) was detected in 21.2% of cows examined in Study 2. The prevalence of endometritis varied among herds, declined with time postpartum (P < 0.05) and was higher in cows recorded as having a peripartum disease (P < 0.01). Cows diagnosed with endometritis were at higher risk of not being detected in oestrus before the start of breeding (P < 0.01), took longer to be inseminated after the start of the seasonal breeding programme (P < 0.01), had a lower first service conception rate (P < 0.01), had lower 56-day and final pregnancy rates (P < 0.05) and took longer to conceive than cows without endometritis (P < 0.05). It is concluded that examination with the metricheck device is more sensitive in detecting endometritis than vaginoscopy. Diagnosis of endometritis with the metricheck device was associated with poorer subsequent reproductive performance.     

Comparison of the cytobrush, cottonswab, and low-volume uterine flush techniques to evaluate endometrial cytology for diagnosing endometritis in chronically infertile mares

Endometritis is the most important cause of infertility in barren mares. The quick method of endometrial cytology (EC) has a relatively high reliability in diagnosing endometrial inflammation in the mare. For reliable cytological results, a collection technique that yields many well-preserved cells representative of a large uterine surface area without causing harm to the reproductive tract is required. The aim of the study was to compare three usually employed techniques for collection of endometrial and inflammatory cells (guarded cotton swab, uterine lavage, and cytobrush) in chronically infertile mares. Twenty Standardbred mares were used. In each mare, samples for EC were collected, first by a cotton swab (DGS), then by a cytobrush (CB), and finally by low volume flush (LVF). The slides were stained using the Diff Quick stain. The following parameters were assessed for each tested technique: background content of the slides; quality of the cells harvested; total cellularity; neutrophils; ratio PMN/uterine epithelial cells; inflammatory cells; vaginal epithelium cells. Categorical variables were compared using contingency tables and Pearson Chi-square tests, whereas continuous variables were compared using one-way analysis of variance (ANOVA); P < 0.05 was considered significant. Samplings by DGS and CB resulted easy and quick to perform via a single operator in all cases. LVF was performed easily, but required the presence of 2-3 players and took more time. The background content of the slides prepared by DGS appeared proteinaceous, slides prepared by LVF appeared contaminated by red blood cells or debris, whereas slides prepared by CB appeared clear. All smears showed a good total cellularity. The CB yielded significantly more cells (P < 0.0001) than DGS and LVF. The DGS produced significant more cells than LVF (P < 0.0001). The DGS produced significantly more (P = 0.003) intact cells than CB and LVF. Distorted cells were significantly (P = 0.001) more frequent in smears by LVF. The CB harvested significantly (P = 0.009) more fragmented cells. CB and LVF produced significantly (P < 0.0001; P = 0.02) more PMNs/HPF than DGS. In smears collected by LVF the proportion of PMNs/uterine epithelial cells was significantly (P = 0.0062; P = 0.0023) higher than in smears by CB and DGS. CB collected a significantly higher (P = 0.0011) proportion of PMNs than DGS. Acute endometritis was diagnosed in 50% (10/20) of the mares by DGS cytological samples, 25% (5/20) by CB, and 75% (15/20) by LVF. Inflammatory cells other than PMN (lymphocytes, macrophages, eosinophils) were collected exclusively by CB method. Epithelial cells from the vagina were only detected in LVF slides. The agreement of the diagnosis of endometritis between the three techniques of collection and between the different criteria adopted to evaluate smears obtained with the same technique was poor (k ≤ 0.3). In conclusion, results show that cytobrush and flush specimens were superior in all parameters to cotton swab smears. Even though the cytobrush technique requires specialized equipment, sample collection by this method was easier, more consistent, and quicker than the lavage method, indicating that the brush would be the preferred collection method for use on field in the mare. More studies are needed to establish criteria for interpretation of inflammation in the mare on cytobrush samples.     

Secretion of prostaglandins and leukotrienes by endometrial cells in cows with subclinical and clinical endometritis

The aims of this study were (1) to measure the secretion of prostaglandin F_2α (PGF_2α), prostaglandin E₂ (PGE₂), leukotriene B₄ (LTB₄), and leukotriene C₄ (LTC₄) by endometrial cells collected by a cytobrush from healthy cows and cows with subclinical and clinical endometritis in the fourth week postpartum, and (2) to evaluate the relationship between the mediators' levels of secretion and the number of polymorphonuclear neutrophils (PMNs) in the uterine smears of cows with subclinical endometritis. The study included cows without any signs of clinical endometritis (n = 63) and cows with clinical endometritis as a positive control (ENDOM, n = 12). Two different threshold ratios (>5% and >18% of PMNs) were used to categorize the cows without clinical signs as with or without cytologic endometritis (CE). Considering the first or second threshold, the animals with CE were included in group CE POS I or CE POS II, whereas the healthy cows were assigned to group CE NEG I or CE NEG II, respectively.     

Prevalence of endometritis and its effects on reproductive performance of dairy cows

Hostein cows (n=141) in five commercial dairy herds in central New York were examined for endometritis by examination of endometrial aspirates for presence of inflammatory cells, principally neutrophils, by endometrial cytology at 40-60 days postpartum. The prevalence of cytologically-diagnosed endometritis was 53%; within herds the prevalence varied from 37 to 74% (P=0.02). There was excellent agreement between two examiners (Kappa=0.864; P<0.0001). Parity did not influence prevalence of endometritis (P=0.53). Cytologically diagnosed endometritis was associated with profoundly impaired reproductive performance; Kaplan-Meier survival analysis revealed lower overall pregnancy rate (P<0.0001). Median days open was 206 for cows with endometritis and 118 for cows free of the condition. Overall, 76% of cows in this study became pregnant by 300 days postpartum; 63% of cows with endometritis and 89% of cows without endometritis were confirmed pregnant by 300 days postpartum (P<0.003). (For these two groups, 69, and 90% respectively, became pregnant during the duration of the study). Pregnancy to first service percentage was lower (11 versus 36%; P=0.001) for cows with than without endometritis, and these cows required more services before 50% became pregnant (3 versus 2; P=0.006). In a second study using 22 cows in a university-owned herd, the prevalence of cytological evidence of inflammation was 100% at 2 weeks postpartum, and dropped to 89, 58, and 41% at 4, 6, and 8 weeks, respectively. Endometritis diagnosed by endometrial cytology late in the voluntary waiting period was highly prevalent and exerted a profoundly detrimental effect on subsequent reproductive performance, making this condition potentially extremely costly to the North American dairy industry.     

Use of reagent test strips for diagnosis of endometritis in dairy cows

The use of leukocyte esterase (LE), protein, and pH tests were evaluated on widely available urinary test strips (Multistix 10 SG; Bayer Corporation, Elkart, IN, USA) on uterine lavage samples as a potential cow-side test for the diagnosis of cytologic endometritis. Uterine lavage samples of 563 lactating Holstein cows between 40 and 60 days postpartum from 28 herds were evaluated. Endometrial cytology was used as the reference for endometritis, with a cutoff point of ≥10% neutrophils. All three (LE, protein, and pH) were increased in cows with cytologic endometritis and the associations were highly significant. Optimal cutoff points determined by receiver operating characteristic analysis for LE, protein, and pH were ≥++, ≥300 mg/dL, and ≥7.0, respectively. Combining the results for LE and pH improved the performance of the test strip, but this resulted in a group of cows (20.6% of cows) which were approximately equally likely (46% with endometritis and 54% without endometritis) to have cytologic endometritis or not, and therefore could not be accurately classified. The direct relationship between reagent strip test and reproductive performance was also evaluated. Reproductive impairment due to endometritis was restricted to multiparous cows; significantly decreased reproductive performance was observed for multiparous cows with lavage fluid LE ≥+++ (154 vs. 115 median days not-pregnant), as well as cows with pH ≥ 7.0 (150.5 vs. 111.5 median days not-pregnant), but not in cows with high protein, even at the highest cutoff point. In conclusion, reagent strip test results were strongly associated with cytologic endometritis and reproductive impairment; however, in comparison with conventional cytology, the performance of reagent strip as an alternative test was relatively poor and may require further refinement.     

Comparison of three diagnostic methods to identify subclinical endometritis in mares

The objective of this study was to compare the accuracy of a uterine swab (US), a cytological brush (CB) and an endometrial biopsy (EB) to detect subclinical endometritis in mares. Cytological and bacteriological results of all three techniques were related to histological occurrence of polymorphonuclear neutrophils (PMNs) in the stratum compactum, commonly known as ‘best standard'; to diagnose endometritis.Samples were taken from 55 mares of different breeds without clinical signs of endometritis. Samples for US, CB and EB were collected, smeared on a microscopic slide and cultured for bacterial growth. Endometrial biopsy samples were additionally stored in 4% formaldehyde for histological analysis. Bacteriological cultures and cytological samples of all techniques were classified as negative (no uterine pathogens in monoculture; < 2% PMNs) or positive (uterine pathogens in > 90% of the grown colonies; > 2% PMNs) for endometritis. Uterine pathogens were diagnosed in 20.0% of the mares. Isolation of pathogens was not associated with positive cytological findings (r = −0.23; P = 0.87). None of the six mares with an Escherichia coli infection (10.9%) showed a positive cytological result. In contrast, two of five mares infected with Streptococcus zooepidemicus had a positive cytological result.Histologically, the presence of PMNs in the stratum compactum was regarded as positive for endometritis when the mare was in diestrus at time of sampling. Compared to the ‘best standard', sensitivity for cytology of CB, US and EB was 0.17, 0.00 and 0.25, respectively. Specificity for cytology of CB, US and EB was 0.83, 0.93 and 0.85, respectively. Sensitivity of uterine culture was 0.25, 0.33 and 0.25 for CB, US and EB, respectively. Specificity for culture of CB, US and EB was 0.80, 0.83 and 0.95, respectively. In conclusion, cytological or bacteriological examinations alone provide a high incidence of false negative results. Sensitivity of cytology combined with bacteriology of CB was 0.42. A combination of a bacteriological and a cytological examination of a CB sample improved the diagnostic performance in subfertile mares. Based on these results, we can recommend the CB to improve the diagnosis of subclinical endometritis in the mare compared to the US alone as currently used routine method.     

Postpartum endometrial cytology in beef cows

The objectives were to characterize postpartum endometrial cytology and to determine the prevalence of subclinical endometrial inflammation and its impact on reproduction in beef cows. Samples for endometrial cytology (low-volume uterine lavage) were obtained from 135 of 137 Angus cows (2-87 d postpartum) in northern Minnesota, 26 d before breeding started. Agreement between examiners for subjective inflammation scores was very high (kappa = 0.971); the correlation between these scores and PMN counts was high (r = 0.83; P < 0.001), validating subjective categorization. The proportion of PMN and large mononuclear cells (principally macrophages) declined with postpartum interval (P < 0.001), whereas small mononuclear cells were consistently present (and not significantly affected by postpartum interval). Pregnancy rate to fixed-time AI was 29% and overall pregnancy rate was 89%. There was no association between cell type and ultimate pregnancy status or day of conception (P > 0.10). Although inflammation later in the postpartum period apparently impaired subsequent reproduction in dairy cows, in cows >50 d postpartum at sample collection in the present study, no cytological parameter significantly predicted final pregnancy status or day of conception. Previous twinning increased the risk of subclinical endometritis (P = 0.02), but not the probability of becoming pregnant (P = 0.14). In conclusion, we inferred that beef cows had the ability to clear uterine inflammation after resumption of ovarian cyclicity.     

Cytological diagnosis of endometritis in the mare: investigations of sampling techniques and relation to bacteriological results

Aim of this study was to compare uterine smears made using the Knudsen catheter, the cytology brush and a uterine culture swab with regard to diagnostic usefulness and the occurrence of neutrophils. Additionally correlation between culture results and the occurrence of neutrophils in uterine smears was investigated. Samples were collected from 340 mares, 81.5% of which were in estrus. Smears made using the cytology brush yielded more endometrial cells per high-power field than those made using the other two instruments (p<0.0001), and a larger proportion had PMNs compared with smears made using the uterine swab (p<0.0001). For smears made with the cytology brush, cultures of β-hemolytic streptococci were more often (p=0.002) accompanied by PMNs than cultures of bacteria other than β-hemolytic streptococci, and there was a positive correlation (r(s)=0.2 p=0.01) between the number of PMNs in smears and the number of colonies of β-hemolytic streptococci. The cytology brush was superior to the other methods because it generated a larger proportion of diagnostic useful smears and the occurrence of PMNs in smears was significantly correlated with the occurrence of cultures of β-hemolytic streptococci.     

The effect of a single administration of cephapirin or cloprostenol on the reproductive performance of dairy cows with subclinical endometritis

This study examined the effect of a single administration of cephapirin iu or cloprostenol im on the reproductive performance of dairy cows with subclinical endometritis. Cows (n = 228) at 20-33 days in milk (DIM) from two commercial dairy farms, determined to be normal for clinical endometritis (based on absence of abnormal uterine discharge on vaginoscopic examination) were enrolled. At enrollment, a thorough reproductive examination was performed, including rectal palpation, ultrasonography (US) and endometrial cytology (EC). The case definition for subclinical endometritis was the presence of >18% neutrophils on EC examination or fluid in uterus (FIU) on US examination. All cows were randomly assigned to receive one of three treatments: 500 mg benzathine cephapirin iu, 500 microg cloprostenol im, or control (no treatment). Reproductive performance was monitored for a minimum of 8 months after treatment. Cows with subclinical endometritis treated with cephapirin or cloprostenol had a significantly increased relative pregnancy rate compared to control [hazard ratios 1.89 (P = 0.01) and 1.70 (P = 0.05), respectively]. In conclusion, a single treatment with cephapirin or cloprostenol at 20-33 DIM significantly improved the reproductive performance of cows with subclinical endometritis.     

The diagnosis and prevalence of subclinical endometritis in cows evaluated by different cytologic thresholds

The aims of our study were to determine (1) how the prevalence of cytologically determined subclinical endometritis varies when using three different cytological threshold ratios to categorize cows as either with or without endometritis, (2) how the number of animals categorized as having endometritis changes from the fourth to the sixth wk postpartum when using each threshold, (3) how subclinical endometritis influences the number of days open, and (4) how the results of cytological and bacterial examinations correlate. To answer these questions, 222 clinically healthy cows in two herds were examined in the fourth (Exam 1) and the sixth wk (Exam 2) postpartum, when endometrial surface scrapings for bacteriologic and cytologic examination were collected by cytobrush from their uterine horns. After each examination, all cows were categorized using three different thresholds: (1) > 18% polymorphonuclear leucocytes in Exam 1 and > 10% in Exam 2, (2) > 8% in both exams, and (3) > 5% in both exams. It was found that: (1) The number of cows categorized as having endometritis increased as the threshold was lowered, and ranged from 18.9% to 75.4% according to herd, time of examination, and the threshold used; (2) with all three thresholds and in both herds, the number of cows categorized as having endometritis in Exam 1 was approximately double that in Exam 2; whereas depending on the herd and the threshold used, 6.1% to 17.0% of the cows that were negative in the first exam were positive in the second, and 7.4% to 33.3% were positive in both exams; (3) cows were open for a significantly greater number of days if categorized as having endometritis with the first threshold in Exam 1 (mean ± SEM 151.5 ± 9.5 vs. 115.9 ± 7.8; P < 0.01), or with either the first or the second threshold in Exam 2 (mean ± SEM 155.0 ± 15.0 vs. 125.1 ± 6.6; P < 0.05); and (4) the most common bacteria were Streptococcus acidominimus and Escherichia coli, and the correlation between cytologic and bacteriologic findings was low (Φ = 0.08 to 0.17 for different tested thresholds). Subclinical endometritis seems to be associated more with the postpartum recovery of the endometrium than with bacterial infection.     

Associations between intrauterine bacterial infection,reproductive tract inflammation,and reproductive performance in pasture-based dairy cows

Reproductive tract bacterial infections, particularly those caused by Escherichia coli and Trueperella pyogenes, can have a negative impact on reproductive performance. It has been hypothesized that the presence of E coli early postpartum may increase the risk of isolation of T pyogenes later postpartum. The objective of the present study was to examine associations between intrauterine bacterial infections with E coli and T pyogenes and any bacterial growth (irrespective of bacterial species), purulent vaginal discharge (PVD), cytologic evidence of endometritis (an increased proportion of polymorphonuclear cells [PMNs]), and reproductive performance. Dairy cows (n = 272) from six herds were examined at Days 0 (median, 2 days in milk), 21 and 42 postpartum. From each cow two intrauterine samples were collected via triple-guarded cytobrush at Days 0 and 21. The first cytobrush was used for bacteriologic culture. Escherichia coli and T pyogenes were isolated by culture, and E coli isolates were assigned to one of four phylogenetic groups using a two-step triplex polymerase chain reaction. In addition, T pyogenes was confirmed by polymerase chain reaction. The second cytobrush was used to prepare a cytology slide. Nucleated cells (n = 200) were categorized as epithelial cells, PMNs, or macrophages. Cows were also assessed for body condition score, PVD score, the presence of a CL, and pregnancy. Statistical analysis was performed using multivariable models. There was no association between the presence of E coli at Day 0 and probability of isolation of T pyogenes 3 weeks later; however, E coli positive cows at Day 0 were more likely to be diagnosed with E coli at Day 21 (relative risk [RR] = 2.0, P < 0.01). Escherichia coli at Day 0 or T pyogenes at Day 21 increased the risk of PVD diagnosis 3 weeks later (RR = 1.9; P = 0.04 and RR = 3.0; P = 0.05, respectively). Cows with any bacterial growth at Day 21, irrespective of species, were less likely to conceive within 3 weeks after the start of the seasonal breeding program (RR = 0.8; P = 0.05). Interestingly, cows with 25% PMNs or greater at Day 0 had shorter time to pregnancy (hazard ratio = 1.32; P = 0.05). Intrauterine bacterial infection may impair reproductive performance but the presence of E coli was not associated with isolation of T pyogenes 3 weeks later. Increased endometrial flux of PMNs in cows early postpartum may be a physiological process and improve reproductive performance.     

Prevalence of bovine subclinical endometritis 4h after insemination and its effects on first service conception rate

The objective of this study was to investigate the prevalence of subclinical endometritis 4 h after AI and its effect on first service conception rate (FSCR) in dairy cows.A total of 201 Holstein-Friesian cows with no signs of clinical endometritis were examined 4 h after first AI for signs of subclinical endometritis. Endometrial samples were collected from the uterus using the cytobrush technique. The proportion of polymorphonuclear cells (PMN) in the cytological sample was used to characterize an inflammation of the endometrium. Cows were categorized into three groups according to the proportion of PMN in the sample. Cows with 0% PMN (n = 115) were assigned to group Zero, cows with >0-15% PMN (n = 59) to group Medium, and cows with >15% PMN (n = 27) to group High. Pregnancy diagnosis was performed between days 38-44 after AI by palpation of the uterus and its contents per rectum.The FSCR was significantly higher in group Medium than in groups Zero and High (57.6% vs. 39.1% and 29.6%). Statistical analysis revealed an interaction between parity and PMN group. Primiparous cows were at higher risk of being classified into group Medium than multiparous cows (OR = 2.27, P = 0.01). Primiparous cows in group Zero had lower odds of pregnancy after first AI than primiparous cows in group Medium (OR = 0.3, P = 0.02). A comparison with cows that were not examined for subclinical endometritis showed that the collection of endometrial samples itself had no effect on FSCR.     

Effect on fertility of human chorionic gonadotrophin and uterine lavage with oxytocin performed after mating in Arabian barren mares

The objective of the present study was to evaluate the beneficial effect of hCG injected immediately after mating in Arabian barren mares treated with uterine lavage and oxytocin. Arabian barren mares (n = 36) with PMIE were subjected to detailed clinical examinations including palpation per rectum, vaginoscopy, and cytological examination. After mating the 36 mares were randomly divided into four groups. The mares in group 1 (n = 10) were immediately after breeding injected with hCG 3000 IU IM. Uterine lavage with 1 L of N-saline containing 4 million IU of crystalline penicillin and 4 g of streptomycin sulphate was performed 4 h after breeding. Then mares received two injections of oxytocin 40 IU IM 2 h apart after 6 h of mating. Mares in group 2 (n = 10) treated with uterine lavage and oxytocin as group 1. While mares in group 3 (n = 10) received uterine lavage only. A control group (n = 6) as group 4 did not received any treatment. The results of clinical examination indicated that 69.4% of PMIE mares were harboring severe endometritis and 30.6% with a moderate form of endometritis. Significant (P < 0.01) increase in lymphocytes were founded in barren mares included in this study. Higher pregnancy rate (P < 0.01) was founded in Arabian barren mares 80% injected with hCG immediately after breeding and uterine lavage and oxytocin. No significant difference was found in mares received uterine lavage and oxytocin and uterine lavage only. In a conclusion, administration of hCG immediately after mating and intrauterine lavage containing antibiotics performed 4 h and two injections of oxytocin 40 IU IM 2 h apart after 6 h of mating had improved fertility of Arabian barren mares.     

High concentrations of myeloperoxidase in the equine uterus as an indicator of endometritis

Intraluminal fluid and excessive abnormal hyperedema are regularly used for the diagnosis of endometritis in the mare, which is routinely confirmed by the presence of neutrophils on endometrial smears. Studies show a relation between neutrophils and myeloperoxidase (MPO), an enzyme contained in and released by neutrophils during degranulation or after cell lysis. This enzyme has been found in many fluids and tissues, and associated with different inflammatory pathologies in the horse. The aims of this study were to assess the presence and concentration of MPO in the equine uterus, and to investigate its relation with neutrophils, and other clinical signs of endometritis. Mares (n = 51) were evaluated for the presence of intraluminal fluid and excessive endometrial edema before breeding, and a small volume lavage and cytology samples were obtained. From 69 cycles, supernatant of the uterine flushes was analyzed with a specific equine MPO ELISA assay to measure MPO concentration. Cytology samples were used for the diagnosis of endometritis. Myeloperoxidase was present in the uterus of all estrus mares in highly variable concentrations. Myeloperoxidase concentrations were significantly (P < 0.05) higher in samples with positive cytologies and in the presence of intraluminal fluid. Occasionally, some samples with negative cytologies showed high MPO concentration, but the opposite was never observed. Cycles presenting hyperedema weren't associated with high concentration of MPO, intraluminal fluid, or positive cytology, making it a poor diagnostic tool of endometritis.     

Involvement of the plasminogen activation system in cow endometritis

The objectives of this study were to investigate the: (a) presence and activity of components of the "plasminogen activators/plasmin" system in dairy cows with or without endometritis; (b) variations in enzyme activity according to the degree of endometritis; and (c) associations between these enzymes and changes in endometrial histology after intrauterine antibiotic treatment. Endometrial biopsies were collected from anestrus (no palpable ovarian structures and milk progesterone <1 ng/ml) Holstein cows, 30-40 days postpartum. On the basis of a vaginoscopic examination, rectal palpation of the cervix and uterus, and endometrial histology, there were 92 cows with endometritis and 20 cows without endometritis. After biopsy collection, each cow was given an intrauterine infusion of 1.5x10(6) IU of procaine penicillin G. In cows with endometritis, genital tract examinations and biopsies were repeated 2 weeks later. Both plasminogen activators (PAs), tissue type (t-PA) and urokinase (u-PA), were immunologically identified in all uterine biopsies. Plasminogen activator activity (PAA) increased, whereas plasminogen activator inhibition (PAI) and plasmin inhibition (PI) decreased in proportion to the degree of inflammation. Two weeks after intrauterine treatment, PAA had decreased significantly in all cows that had reduced severity of endometrial inflammation and had increased significantly in all cows with increased severity of inflammation. The change in the degree of inflammation depended upon plasminogen activator activity; cows with higher PAA were more likely to improve. In conclusion, there was evidence for a role of the plasminogen activation proteolytic system in bovine endometritis.     

Effects of ecbolic agents on measurements of uterine involution in the mare

Thirteen postparturient mares were used to investigate the effects of ecbolic agents on the rate of uterine involution. Mares were randomly assigned to one of three treatment groups: Group S = intravenous injection of 2 ml saline twice daily for 10 days post partum (n=4); Group O = intravenous injection of 20 units oxytocin twice daily for 10 days post partum (n=4); and Group P = intramuscular injection of 500 mcg fluprostenol twice daily for 10 days post partum (n=5). Ovulation was determined by daily transrectal ultrasonographic examination of the ovaries. On Days 6, 11 and 16 post partum, transrectal ultrasonography was used to measure cross-sectional diameters of the uterine body, uterine horns and fluid within the uterine lumen. Uteri were swabbed for aerobic bacteriologic culture on Days 11 and 16 post partum. Uterine biopsies were obtained from the base of the previously gravid uterine horn on Days 11 and 16 post partum for subjective assessment of endometritis and morphometric analysis of endometrial histoarchitecture. Mean values for all measurements of uterine involution did not differ among groups (P>0.05). For all mares, the diameter of luminal fluid was not correlated to diameter of the uterine body or uterine horns, or to morphometric measurements of endometrial histoarchitecture of the previously gravid uterine horn (P>0.05). Likewise, accumulation of fluid within the uterine lumen was not associated with endometritis or recovery of potential bacterial pathogens (P>0.05). Mean diameter of the previously gravid uterine horn was negatively correlated with morphometric measures of endometrial histoarchitecture of the previously gravid uterine horn (P<0.01).