Postpartum uterine diseases in dairy cows : a review with emphasis on subclinical endometritis

In this review, updated and precise definitions of the most common postpartum uterine diseases in dairy cows are provided. An aberrant uterine environment at inappropriate stages of the reproductive cycle inflicts damage to gametes and zygotes, impairing the reproductive performance of dairy cows. This involves major economic losses for the milk production unit. Consequently, an accurate diagnosis of postpartum uterine diseases is indispensable for practitioners to set up a prompt and efficient treatment. This review furthermore emphasizes on the new perspectives regarding diagnosis and treatment of subclinical endometritis, a highly prevalent uterine disease that is often overlooked by practitioners while causing major reproductive problems. Based on a more profound clinical understanding of the postpartum uterine disease complex, practitioners will be able to better use the available diagnostic tools and therefore apply a more efficient therapeutic approach

Post Partum Bacteriology in Cows (Preliminary Date)

The relationship of various clinical forms of uterine inflammation to bacterial contamination and the applicability of hydrogen peroxide for the intrauterine treatment of clinical endometritis was the subject of this trial. Uterine contamination was compared among groups of cows according to clinical findings on days 6 ± 3: MM, n = 7 (mild or severe puerperal metritis), SM, n = 7 (cows with severe puerperal metritis) and CM, n = 7 (cows without symptoms of puerperal metritis). After 21 ± 3 the seam cows (mild or severe clinical endometritis and controls without symptoms of the disease: MM, n = 7, SM, n = 7 and CM, n = 7). The applicability of 3% hydrogen peroxide was evaluated on cows after infusion 80 ml of the solution, clinical as well as a bacteriological examination of uteri in cows suffering from a postpartum pathology. A wider bacterial spectrum was found in the cows on day 6 ± 3 compared to day 21 ± 3. Arcanobacterium pyogenes and Bacillus spp were the main uterine contaminant in cows suffering from all clinical types of uterine inflammation while this bacterium was not shown to be present in any of the control cows. The results show an important role of A. pyogenes in the etiopathogenesis of all clinical forms of uterine inflammations in postpartum cows and support the use of 3% hydrogen peroxide for intrauterine treatment of clinical endometritis even though sufficient antibacterial effects of the treatment are still to be confirmed.Keywords: inflammations, uterus, cows, uterine contaminants (Arcanobacterium pyogenes, Bacillus spp), puerperal metritis, lochia, Escherichia coli, etc

Immunohistochemical Characterization of Leukocytic Subpopulations in Chronic Endometritis

Objective: We analyzed the histologic and immunohistochemical changes in the endometrial leukocytic subpopulations to determine which of them are characteristic of chronic endometritis

Infection and Infertility in Mares

In cyclic mares, the uterine environment can easily disturbed due to inflammatory processes that occur secondary to microbial invasion. Different aerobic and anaerobic bacteria can enter the uterus during natural mating, artificial insemination, reproductive examination or parturition. The postpartum period is a critical phase since due to relaxation of the uterus and cervix may favor recurrent infections air intake (pneumovagina) or urine collection in mares with poor perineal conformation. Infections are mainly caused by opportunistic or commensal microorganisms, such as Streptococcus zooepidemicus, hemolytic Escherichia coli and Staphylococcus aureus. Other microorganisms like Taylorella equigenitalis, Klebsiella pneumoniae and Pseudomona aeruginosa are transmitted through venereal route. Regarding to the fungal endometritis, the most common fungi include Candida and Aspergillus. These microorganisms cause infertility as a result of repeated inseminations during the breeding season and proliferate when the natural immune system is weakened in mares with advanced age and multiparous, or after repeated use of antibiotics. Indeed, in susceptible mare to endometritis, uterine defense mechanisms involving phagocytosis and opsonization by neutrophils, local synthesis of antibodies, mucociliary activity, vascular and myoelectric activity permeability are compromised, leading to fluid accumulation in response to inflammation and infertility

Endometrial cytology, biopsy, and bacteriology for the diagnosis of subclinical endometritis in grazing dairy cows

The objectives of this study were to assess the agreement between endometrial cytology and uterine biopsy for the diagnosis of subclinical endometritis (SEND) in grazing dairy cows, the interobserver agreement of the biopsy's readings, and the bacterial population isolated from the uterus of cows having SEND. In experiment 1, lactating Holstein cows (n. = 44) 31 to 59. d in milk (DIM) at sampling were enrolled. Clinical endometritis was diagnosed by direct evaluation of vaginal discharge and SEND by endometrial cytology evaluation. Two hundred cells per smear were counted to determine the percentage of polymorphonuclear neutrophilic leukocytes (PMNL). Cut-off values used were ≥8% PMNL at ≤33 DIM, ≥6% PMNL at 34 to 47 DIM, and ≥4% PMNL at ≥48 DIM. Biopsies were assessed blindly by 2 observers who categorized them into 4 groups according to their inflammatory changes: none, minimal, moderate, and severe inflammatory changes. Data were analyzed using the kappa coefficient and logistic regression. In experiment 2, lactating Holstein cows (n. = 60) 21 to 62 DIM were enrolled. Clinical endometritis and SEND were diagnosed as previously described. Samples were cultured for aerobic and anaerobic bacteria by routine methods of bacteriological testing. Data were analyzed with logistic regression. In experiment 1, little agreement was observed between cytology and biopsy outputs (kappa. = 0.151), and strong agreement between the 2 operators (kappa. = 0.854). The likelihood of having a normal biopsy (no inflammatory change) was greater for healthy cows than for those having SEND (odds ratio. = 13.145). The probability for getting normal uterine tissue decreased 2.1% for every increasing percentage point in PMNL. In experiment 2, no bacteria were isolated from cows with SEND, coagulase-negative staphylococci were commonly isolated from healthy cows, and Trueperella pyogenes was frequently isolated from cows with clinical endometritis. The likelihood of isolating T. pyogenes from uterine samples increased with the percentage of PMNL (odds ratio. = 1.100). In conclusion, biopsy showed low agreement with cytology for the diagnosis of SEND. Nevertheless, fertility trials using uterine biopsies to predict pregnancy outcomes are needed to determine its diagnostic usefulness. Finally, bacteriology would not be recommended as a diagnostic tool because no bacteria were isolated from cows with SEND.Facultad de Ciencias Veterinaria

Subclinical Endometritis in Dairy Cattle

Subclinical endometritis is recognized as a cause of poor reproductive performance in dairy cows. Inflammation of the endometrium persisting after postpartum uterine involution has been related with prolonged calving-conception intervals and low fertility in dairy cows. The subclinical nature of this condition makes it necessary in the use of endometrial cytology or biopsy for diagnosing it. There are some controversies among authors in relation to the postpartum period from which a physiological endometrial inflammation should be considered a pathological subclinical endometritis. Therefore, depending on the sampling period after calving, different studies establish a different degree of polymorphonuclear leukocyte infiltration as cutoff point to diagnose subclinical endometritis. Controversies also exist regarding the pathogenesis of the disease and its consequences on the fertility of dairy cattle. The aim of this chapter was to review the current knowledge on this uterine pathology

The Pathological Changes affecting the Endometrium: A Contribution towards their Classification.*

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Determination of ceftiofur derivatives in serum, endometrial tissue, and lochia in puerperal dairy cows after subcutaneous administration of ceftiofur crystalline free acid

Puerperal uterine infections are often associated with decreased reproductive performance in dairy cows. Routine treatment protocols include the systemic administration of antibiotics. Antibiotic drugs, however, should be administered daily over at least 5 d. The objective of this study was to determine concentrations of ceftiofur derivatives in serum, endometrial tissue, and lochia after subcutaneous administration of ceftiofur crystalline free acid in 6 clinically healthy puerperal dairy cows with normal parturition. Samples were taken immediately before treatment, 2 h after, and then every 24 h over a 7-d period. Concentrations of ceftiofur derivatives were quantified using an HPLC assay. In serum and endometrial tissue, ceftiofur derivatives could be detected above the reported minimum drug concentrations required to inhibit relevant pathogens such as Escherichia coli and Arcanobacterium pyogenes over a 7-d period. Concentrations of desfuroylceftiofuracetamide at 5 d after administration of ceftiofur crystalline free acid were 1.21±0.61 μg/mL in serum, 0.86±0.61 μg/mg in endometrial tissue, and 0.96±1.15 μg/mL in lochia. In lochia, mean concentrations of ceftiofur derivatives also remained above the minimal inhibitory concentration of relevant pathogens, but showed greater variations between cows

The relationship between endometrial cytology during estrous cycle and cutoff points for the diagnosis of subclinical endometritis in grazing dairy cows

The objectives of this study were to assess the effect of the stage of estrous cycle on the percentage of endometrial polymorphonuclear cells (PMN) obtained by cytobrush to determine cutoff values for the diagnosis of subclinical endometritis under pastoral conditions, to measure the prevalence of subclinical endometritis 21 to 62d in milk (DIM), and to evaluate the effect of subclinical endometritis on reproductive performance in grazing dairy cows. The first experiment was conducted on a commercial dairy farm in Buenos Aires province (Argentina), where 17 postpartum cyclic dairy cows without clinical endometritis were selected and synchronized by Ovsynch protocol. Endometrial cytology (cytobrush technique) and blood (tail vessels) samples were obtained on d0, 4, 11, and 18 of the estrous cycle (corresponding to estrus, metestrus, diestrus, and proestrus, respectively) and used for measuring percentage of PMN and P4 concentration, respectively. The percentage of PMN was determined 3times by blinded count by 2 operators. Data were analyzed with PROC MIXED, PROC GENMOD, and PROC FREQ from SAS 9.1. The percentage of PMN did not vary with the stage of the estrous cycle. In addition, PMN counts were below any of the reported thresholds in this study (4%) for most of the cows. Therefore, the risk for false positive test results as a consequence of physiological changes in the counts of PMN during estrous cycle is low. The second experiment was conducted on 4 commercial dairy farms in Buenos Aires province (Argentina), where lactating Holstein dairy cows (n = 418) 21 to 62 DIM without clinical endometritis were studied. Samples of endometrial cytology were collected with the cytobrush technique. Data were analyzed with receiver operator characteristic curves with Sigmaplot 10.0, and with PROC GLIMMIX, PROC PHREG, and PROC LIFETEST from SAS 9.1. Cutoff values for the diagnosis of subclinical endometritis in grazing dairy cows are 8% PMN for 21 to 33 DIM, 6% PMN for 34 to 47 DIM, 4% PMN for 48 to 62 DIM, and overall 5% PMN for 21 to 62 DIM; the prevalence of subclinical endometritis 21 to 62 DIM was 17%. Finally, subclinical endometritis diagnosed at 21 to 62 DIM decreases the hazard for pregnancy (hazard ratio = 0.668; 95% confidence interval = 0.492-0.909) and increases the calving to conception interval by d30 compared with normal cows (median 95% confidence interval = 133 vs. 93, respectively).Facultad de Ciencias Veterinaria