Therapeutic efficiency of antibiotics and prostaglandin F2α in postpartum dairy cows with clinical endometritis: an evidence-based evaluation

General and comparative aspects of endometritis in domestic species: A review

Endometritis is a leading cause of sub- and infertility in domestic animal species. The healthy uterus is colonized by commensal bacteria, viruses and yeast/fungi that represent the nonpathogenic microbiota. A shift in the number or type of organisms accompanied by immune dysfunction, however, may trigger uterine infection and inflammation. Metritis is associated with inflammation of all uterine layers (endometrium, myometrium and perimetrium), whereas endometritis is a more superficial inflammation involving solely the endometrium. Endometritis generally occurs at two time points in domestic animal species, postpartum and postmating. Postpartum endometritis may chronically persist, either as a low-grade disease that often manifests as a vaginal discharge but not a systemic illness (in some species termed clinical endometritis) or sometimes subclinical where features are only detected by endometrial sampling. Contamination of the uterus at the time of mating occurs by direct deposition of semen (ejaculated or artificially inseminated) into the uterus. Improper drainage of the ejaculatory fluid or an inadequate immune response may result in persistent mating-induced endometritis. Both postpartum and postmating endometritis interferes with fertility by creating a suboptimal environment for embryo development and placentation, and chronic endometritis may have an impact on sperm survival and fertilization ability. In the postpartum animal, there may also be changes in milk production and maternal behaviour, which can affect offspring health and survival. Preventive strategies for endometritis largely depend on monitoring their known risk factors, which are sometimes specific with regard to the species. Effective, nonantibiotic therapy for endometritis is not available to date. Overall, extensive research has been performed in cattle and horses to unravel key aspects of endometritis, but in sows and bitches, the available literature is scant. Thus, the need and opportunity to investigate the condition vary considerably among domestic species and necessitate their comparative assessment. This article reviews general and comparative aspects of the diagnosis and classification, pathogenesis, preventive strategies and therapeutics of endometritis in domestic species with a specific focus on cows, mares, sows and bitches.

Oxytetracycline Persistence in Uterine Secretion after Intrauterine Administration in Cows with Metritis

Simple Summary

Puerperal metritis in cows involves the acute inflammation of the uterus, which is often treated with antibacterial drugs. Restrictions on the use of antibiotics in veterinary medicine require the very precise selection of an antibiotic based on its pharmacokinetics and on sensitivity tests of pathogenic bacteria. This study aimed to evaluate the changes in oxytetracycline levels in uterine secretion over time after intrauterine administration in cows with metritis in relation to the sensitivity of pathogenic bacterial isolates. The concentrations of oxytetracycline in the uterine secretions were higher than the minimum inhibitory concentrations against pathogenic bacteria, provoking the infection of the uterus. Higher concentrations were measured in milk rather than in plasma. The intrauterine infusion of oxytetracycline for three consecutive days led to the alleviation of the inflammation and the restoration of the estrus cycle in cows. The local intrauterine administration of oxytetracycline requires the monitoring of the withdrawal time of milk to ensure consumer safety.

Abstract

Puerperal metritis in cows is often treated with antibacterial drugs. The prudent use of antibiotics in farm animals requires state-of-the-art knowledge of their pharmacokinetics and data from sensitivity tests of pathogenic bacteria. Changes in oxytetracycline levels in the uterine secretion over time after intrauterine administration in cows with metritis were evaluated in relation to the sensitivity of pathogenic bacterial isolates. Oxytetracycline levels in plasma, milk and uterine secretion were determined via LC–MS/MS analysis. Pathogenic bacteria were isolated and their sensitivity to oxytetracycline was determined. The concentrations of oxytetracycline in the uterine secretion were 433.79 (39.17–1668.76) µg·mL⁻¹ six hours after the third application at a dose of 8 mg/kg and 84.33 (1.58–467.55) µg·mL⁻¹ 96 h after the last treatment. These levels were higher than the minimum inhibitory concentrations—namely, between 4 and 64 µg·mL⁻¹—against pathogenic isolates Trueperella pyogenes, Streptococcus intermedius, Escherichia coli and Bacillus pumilis. Higher concentrations over time were measured in milk rather than in plasma, indicating the need to monitor the withdrawal time for milk. The intrauterine infusion of oxytetracycline for three consecutive days resulted in the successful treatment of metritis in terms alleviating inflammation and restoring the estrus cycle in cows.

In vitro effect of tetracycline antibiotics on Trueperella pyogenes isolated from cows with metritis

Trueperella pyogenes is associated with endometritis and metritis in cows. Traditionally these diseases are treated with antibiotics while new approaches include application of the mucolytic N-acetylcysteine. Therefore the study aimed to evaluate the sensitivity of clinical Trueperella pyogenes isolates (n=2) to oxytetracycline, doxycycline, N-acetylcysteine and their combinations. The potential for biofilm formation with/without tested drugs was investigated by the method of crystal violet staining. Minimum inhibitory concentrations (MIC) of oxytetracycline for T. pyogenes 1 and 2 were 16 and 64 µg/mL, respectively. MIC of doxycycline for both isolates was 32 µg/mL and for N-acetylcysteine - 8 mg/mL. Both Trueperella pyogenes isolates did not form biofilm. The growth of T. pyogenes 1 cultured in the presence of either oxytetracycline or doxycycline (0.0078–128 µg/mL) under conditions for biofilm formation was significantly inhibited at concentrations ≥ 1 μg/mL and 8 μg/mL, respectively. The growth of T. pyogenes 2 was not affected by the antibiotics. N-acetylcysteine at ≥ 4 mg/mL resulted in significant inhibition of the growth of both isolates and its combinations with the antibiotics did not inhibit their growth. The effect of N-acetylcysteine should be validated in clinical settings but its combinations with tetracyclines were not able to improve the sensitivity of T. pyogenes, isolated from cows with clinical metritis.

Effect of intrauterine infusion of two cephalosporins, ceftazidime and cephapirin, on uterine bacterial load and uterine horn diameter in bovine subclinical endometritis

This study aimed to evaluate the effect of intrauterine infusion of ceftazidime and cephapirin on uteri­ne bacterial load and uterine horn diameter in bovine subclinical endometritis. At 7-8 weeks postpartum, a total of 122 cows suffering from subclinical endometritis were divided into three groups. Group I cows were intrauterinely (IU) infused with 2 g ceftazidime diluted with 50 mL saline; group II cows were IU infused with 2 g cephapirin diluted with 50 mL saline; and group III cows were kept as untreated control. Vaginal examination, ultrasonography and bacterial examination were done before treatment programme and later repeated twice at 10-day intervals. Staphylococcus spp., Klebsiella spp., Streptococcus spp., Escherichia coli and Proteus spp. were isolated. After the end of the treatment programme, proportions of cows infected with Staphylococcus spp. and Streptococcus spp. were significantly (P<0.05) decreased in ceftazidime and cephapirin groups. However, proportions of cows infected with Escherichia coli were significantly (P<0.05) decreased in the ceftazidime group only. Uterine bacterial loads in ceftazidime and cephapirin groups were significantly decreased (P<0.05). Mean uterine horn diameters in ceftazidime group (2.44±0.03 cm) became significantly lower (P<0.05) than those in cephapirin (2.70±0.04 cm) and control (3.06±0.06 cm) groups. Conception rate in ceftazidime group (80.95%) was significantly (P<0.05) higher than rates recorded in cephapirin (64.00%) and control (26.67%) groups. In conclusion, ceftazidime and cephapirin decreased uterine bacterial load. Moreover, ceftazidime significantly reduced uterine horn diameter compared to the other groups and was associated with significantly higher conception rate. Thus, ceftazidime is recommended for treatment of subclinical endometritis in dairy cows.

Serum biochemical profile in buffalo endometritis and impact of treatment with PGF2α and intrauterine gentamicin infusion on postpartum reproductive performance

Improving reproductive performance of repeat breeder buffalo cows due to clinical endometritis is crucial in overcoming infertility problems in buffalo cows. The aim of the present study was to use PGF2α and/or gentamicin 10% for treatment of endometritis and to determine biochemical parameters in serum that could be used to diagnose endometritis in buffalo cows. A total of 64 anestrous buffalo cows were assigned into one of five treatment groups: group one (n = 9) buffalo cows were physiological normal cows and served as a control group; group 2 buffalo cows had endometritis, but were not treated (n = 10); group 3 buffalo cows had endometritis and were treated with intrauterine delivery of 100 ml of a 10% gentamicin sulfate solution in three times within 1 week (n = 15); group 4 buffalo cows received two I.M. doses of PGF2α (2 ml Estrumate IM) at the time of corpus luteum dominance (n = 15) (treatment 4 does not make sense as you stated that the cows were in anestrus) on the ovary; group 5 buffalo cows received two IM doses of PGF2α at an 11 day interval and the 10% gentamicin solution as described for group 3. Serum samples were collected from control, pre-treated, and post-treated buffalo cows with endometritis to evaluate the diagnostic biochemical parameters. The days to first estrus (DFE), number of services per conception (S/C), days open (DO), and pregnancy rate (Preg) were the measures for determining reproductive performance for the buffalo cows. The buffalo cows treated by gentamicin and PGF2 exhibited their first estrus earlier than cows in the other four groups of cows. The number of days open for control cows was greater (P < 0.05) than for the other groups and the control cows, as were the number of services per conception (P < 0.05) and pregnancy rate (30%: P < 0.05). The receiver operating characteristic (ROC) curve was used to identify biochemical parameters in serum to predict endometritis. Creatine kinase (CK), aspartate aminotransferase (AST), and concentrations of total bilirubin and immunoglobulins in serum were greater (P < 0.05), while serum albumin values were lower (P < 0.05) in serum of buffalo cows with endometritis. From the ROC analyses, CK was the most predictable biomarker for endometritis with an area under the curve of 0.889, sensitivity of 80%, and specificity of 100% (P < 0.001). In conclusion, the use of gentamicin and PGF2 for treatment of endometritis improves the reproductive performance of buffalo cows, and concentrations of CK serve as an aid for diagnosing endometritis.Graphical abstract.

Oxytetracycline Pharmacokinetics After Intramuscular Administration in Cows with Clinical Metritis Associated with Trueperella Pyogenes Infection

Systemic therapy with oxytetracycline is often used for treatment of clinical metritis although data about its penetration into the uterus and uterine secretion are lacking. Uterine secretions and milk from six cows with clinical metritis were collected for microbiological assay. The animals were treated intramuscularly with long-acting oxytetracycline (20 mg/kg) and samples of plasma, milk and uterine secretions were collected for determination of the antibiotic concentrations by HPLC-PDA analysis. Pharmacokinetics of the antibiotic and in silico prediction of its penetration into the uterus were described. Trueperella pyogenes with MIC values of 16-64 µg mL-1 was isolated (n of cows = 4) from uterine secretions. Oxytetracycline showed fast absorption and penetration in the uterine secretions and milk. No change of withdrawal time for milk was necessitated in cows with clinical metritis. Maximum levels in uterine secretions and predicted concentrations of oxytetracycline in the uterus were lower than MIC values. Systemic administration of long-acting oxytetracycline did not guarantee clinical cure and was not a suitable choice for treatment of clinical metritis associated with Trueperella pyogenes. The appropriate approach to antibiotic treatment of uterine infections of cows requires knowledge on penetration of the antibiotics at the site of infection and sensitivity of pathogens.

Efficient treatment of chronic endometritis through a novel approach of intrauterine antibiotic infusion: a case series

BACKGROUND

Early diagnosis and efficient management of Chronic Endometritis (CE) in patients seeking fertility treatment are two components every practitioner wishes to address. With respect to endometrial restoration, antibiotic treatment appears to perform well. However, regarding the improvement of In Vitro Fertilization (IVF) success rates, literature evidence is inconclusive, and consensus on optimal treatment has yet to be reached. This manuscript uniquely brings to literature the first report on effective employment of intrauterine antibiotic infusion to treat CE and contribute to addressing the infertility related to it.

CASE PRESENTATION

In this case series, we present 3 patients reporting numerous previous failed IVF attempts accompanied with diagnosed CE which failed to be properly treated in the past. Following initial assessment in our clinic and verification of CE findings, an oral antibiotic regime was administered based on the infectious agent detected. Re-evaluation concluded slightly improved microbiological environment in the endometrium but persisting inflammation. Antibiotic intrauterine infusion was proposed to the patients as an alternative practice. All our patients achieved a pregnancy shortly following intrauterine treatment with one patient reporting a live birth of twin babies and two patients currently reporting an ongoing pregnancy.

CONCLUSIONS

The implications of this case series contribute to medical knowledge and extend to both effective treatment of CE and subsequent management of related infertility. The current line of treatment of CE through oral antibiotic regimes highlights the need for exploring new options and calls for larger studies on the clinical implication of their use. This novel approach enabled natural conception for patients presenting with established Recurrent Implantation Failure (RIF) having undergone numerous futile IVF attempts. The clinical impact from the practitioner's perspective is considerable allowing for an alternative line of treatment that merits further investigation.

Randomized clinical trial to evaluate the efficacy of prostaglandin F2α to treat purulent vaginal discharge in lactating dairy cows

The objectives of this study were (1) to assess the effect of purulent vaginal discharge (PVD) on reproductive performance using a 4-point vaginal discharge score (VDS) and (2) to evaluate the effect of PGF2α treatment in cows with PVD on reproductive performance. Holstein cows (n = 2,473) from 1 commercial dairy farm had their vaginal discharge scored at 32 ± 3 d in milk (DIM) using a 4-point scale. Cows were also scored for body condition score and had their ovaries examined using transrectal ultrasound. A VDS-2 or greater was used to define PVD. Cows with PVD were assigned to receive 2 doses of 500 µg of PGF2α analogue (n = 277; Cloprostenol; PGF Veyx forte, Veyx Pharma Ltd., Schwarzenborn, Germany) 14 d apart (odd ear tag number) or remained untreated (n = 272; even ear tag number). All cows not detected in estrus at 90 ± 3 DIM were enrolled into a timed artificial insemination (AI) protocol. The effect of VDS and the effect of PGF2α in cows with PVD on reproductive performance were evaluated separately. First service conception risk (FSCR), time to first AI, and time to pregnancy were used as indicators for reproductive performance. Data were analyzed with Cox's regression and mixed logistic models. The prevalence of PVD was 22.2% (548/2,473). We detected an interaction of parity and VDS for FSCR and time to pregnancy. In primiparous cows, VDS had no effect on FSCR and time to pregnancy. In multiparous cows, VDS had an effect on FSCR and time to pregnancy. Multiparous cows having a VDS-2 or a VDS-3 had decreased odds of pregnancy at first AI compared with cows having a VDS-0. Multiparous cows with VDS-1 or VDS-3 had a decreased hazard of conceiving within 200 DIM. The treatment effect of PGF2α was conditional on parity. In primiparous animals with PVD without a corpus luteum present at 32 DIM, treatment with PGF2α reduced FSCR. Irrespective of the presence of a corpus luteum, treatment with PGF2α decreased the hazard of conceiving within 200 DIM in primiparous cows. Although multiparous cows with PVD treated with PGF2α had increased odds of pregnancy at first AI, no treatment effect was observed on the hazard of conceiving within 200 DIM. Our results do not support the blanket use of PGF2α as a treatment option in postpartum dairy cows having PVD.

Effect of puerperal metritis on reproductive and productive performance in dairy cows in Argentina

The objectives of this study were to evaluate the reproductive and productive performance of dairy cows with and without puerperal metritis and to evaluate the effectiveness of using a long-acting ceftiofur preparation. Dairy cows in one dairy farm, calving from July 2009 to January 2010, were examined between 3 and 14 days postpartum and classified on the basis of vaginal discharge into three groups: cows with normal discharge (control; C); cows with a bloody mucus purulent or pathologic nonfetid discharge (PnFD), and cows with bloody mucopurulent or purulent fetid discharge (PFD). Cows in C and PnFD groups were not treated, whereas those in the PFD group were randomly allocated to receive 2.2 mg/kg of ceftiofur subcutaneously behind the ear (PFD-T) or remain untreated (PFD-No T). From the 640 cows examined, 58.2% formed the C group, 13.4% formed the PnFD group, and 28.4% formed the PFD group. Survival curves differed between cows in the C group and PFD-No T group (P = 0.0013) and between PFD-No T versus PFD-T group (P = 0.0006). Survival curves of PnFD were intermediate and did not differ from those in the C group (P = 0.2) and PFD-T group (P = 0.1) but tended to be different from the PFD-No T group (P = 0.056). The postpartum interval to achieve a 25% pregnancy rate was 72 days for cows in the C group, 73 days for the PFD-T group, 83 days for PnFD group, and 95 days for the PFD-No T group. The chance of pregnancy in a cow in the C group was 1.98 times higher (95% confidence interval = 1.33, 3.08) and in cows in the PFD-T group was 2.16 times higher (95% confidence interval = 1.37, 3.50) than that in the PFD-No T group. Finally, the chance of pregnancy in cows in the PnFD group tended to be higher (P = 0.08) than that in the PFD-No T group but did not differ from the other two groups. Cumulative 305-day milk production was higher (P < 0.0001) in C group than those with vaginal discharge, regardless of fetidness and regardless of treatment. It is concluded that puerperal metritis affects the reproductive and productive performance of dairy cows and the treatment with ceftiofur was effective in reducing the adverse effects on reproductive performance but not on milk production.

Strategies for the treatment of dairy cows at high risk for postpartum metritis and for the treatment of clinical endometritis in Argentina

The objectives of this study were to evaluate the efficacy of (1) administering ceftiofur hydrochloride in dairy cows with calving-related disorders to prevent metritis and (2) a combination of GnRH and PGF2α for the treatment of clinical endometritis, under Argentinean dairy farming conditions. Cows at high risk (HRC) for metritis (dystocia, RFM >12 h postpartum, hypocalcaemia, twins, or stillbirth) were randomly assigned to receive either 1.1 mg/Kg of ceftiofur hydrochloride on three consecutive days (HRC treated group HRCT, n = 110) or remained untreated (HRC control group HRCC, n = 126). Cows with low risk (LRC, no calving-related disorders, n = 868) did not receive any treatment (LRC group, n = 868). All cows were examined for metritis between days 4 and 10 and for clinical endometritis between 24 and 30 days postpartum. The body condition score (BCS) was recorded at both examinations. Cows with endometritis at days 24 to 30 postpartum received either 1.5 mg of D-cloprostenol (PGF; n = 129) or 100 μg of GnRH followed by D-cloprostenol after 7 days (GnRH+PGF, n = 119). There was no overall effect of treatment on the incidence of metritis or on time to pregnancy. Treatment, however, reduced the incidence of metritis in cows with high BCS (HRCT = 24.0 %, HRCC = 38.5 %) but had no effect in cows with low BCS (HRCT = 38.7 %, HRCC = 37.5 %). The proportion of pregnant cows by days in milk was greater (P < 0.01) in LRC group compared with that of the HRCT and HRCC groups. No significant differences were found between groups PG and PG+GNRH. GnRH+PGF treatment, however, tended (P = 0.06) to increase pregnancy rate in cows with a moderate loss of BCS (76.5 vs 65.2 %) but tended to reduce pregnancy rate (54.5 vs 76.0 %) in cows with a more pronounced loss in BCS (>0.75 points).

Therapy of bovine endometritis with prostaglandin F2α: a meta-analysis

The objective of the conducted meta-analysis was to assess the efficacy of the treatment of bovine endometritis with PGF(2α) by statistical means. Postpartum uterine infections have a high prevalence and a very negative effect on reproductive performance in dairy cattle. Because of a wide discordance between research results, a meta-analysis of the efficacy of the treatment of bovine endometritis with PGF(2α) was conducted. A comprehensive literature search was performed using online databases to reveal a total of 2,307 references. In addition, 5 articles were retrieved by reviewing citations. After applying specific exclusion criteria and evaluating specific evidence parameters, 5 publications, comprising 6 trials, were eligible for being analyzed by means of meta-analysis. Data for each trial were extracted and analyzed using meta-analysis software Review Manager (version 5.1; The Nordic Cochrane Centre, Copenhagen, Denmark). Estimated effect sizes of PGF(2α) were calculated on calving to first service and calving to conception interval. Prostaglandin F(2α) treatment of cows with chronic endometritis had a negative effect on both reproductive performance parameters. Heterogeneity was substantial for calving to first service and calving to conception interval [I(2) (measure of variation beyond chance)=100 and 87%, respectively]; therefore, random-effects models were used. Sensitivity analysis as well as subgroup analysis showed that the performance of randomization was influential in modifying effect size of PGF(2α) treatment. The funnel plot illustrated a publication bias toward smaller studies that reported a prolonged calving to conception interval after a PGF(2α) treatment. We conclude that the investigation of this subject by means of meta-analysis did not reveal an improvement of reproductive performance of cows with endometritis after treatment with PGF(2α). Furthermore, there is a shortage of comparable high quality studies investigating reproductive performance after PGF(2α) treatment of cows with chronic endometritis.

Clinical trial of treatment programs for purulent vaginal discharge in lactating dairy cattle in New Zealand

Studies of treatment of postpartum endometritis in dairy cows indicate that prostaglandin (PGF2α) might result in similar outcomes as intrauterine antibiotics, but the effect might depend on the presence of a CL. The objective was to compare reproductive performance in cows with purulent vaginal discharge treated on the basis of having or not having a CL (CL-dependent treatment; CLdep), versus treatment of all affected cows with an intrauterine antibiotic alone. Cows (N = 756) from 36 seasonal calving dairy herds in New Zealand were enrolled on the basis of having a vaginal discharge score (VDS) ≥2 (mucus with flecks of pus or more purulent) after examination with the Metricheck device (Simcro, Hamilton, New Zealand) and ≥14 days after calving. The presence of a CL was assessed by transrectal palpation. Cows were randomly assigned within farm to be treated with an intrauterine antibiotic (0.5 g cephapirin) irrespective of CL status, or treated with PGF2α if a CL was present and cephapirin if a CL was not present (CLdep). The VDS was reassessed 14 days later. Cows were bred using standard practices and pregnancy was tested to define the date of conception. The proportion of cows clinically cured (i.e., with a VDS ≤1 at reexamination) did not differ between treatment groups (0.82 ± 0.03 vs. 0.80 ± 0.03) for the group of cows treated with an intrauterine antibiotic irrespective of CL status and the CLdep groups, respectively (P = 0.66). The proportions of cows submitted for AI by 21 days into the breeding program, pregnant to first breeding, pregnant by 42 days into the breeding program, and at the end of the breeding program, and the interval from the start of the mating program to pregnancy did not differ among treatment groups. Cows that had positive VDS (i.e., >1) at Day 14 after treatment had lower proportions of conception and pregnancy than those with lower (<2) VDS. A treatment protocol in which cows with purulent vaginal discharge with a palpable CL were treated with PGF2α and those without a CL with intrauterine cephapirin resulted in reproductive performance that was not inferior to treating all cows with an intrauterine antibiotic.