Skip to content
EvidenceHelixEvidenceLib · Scientific Encyclopedia
⌘ K

Scientific library

EvidenceLib encyclopediaAll articles A–Z2,835Open textbooks209Open-access articles1,406Cancer study catalog458How it is made

My workspace this browser

Saved pages0Notes & annotations0

Recently viewed

Explore by field

Cancer and Oncology182Genetics and Genomics170Neuroscience185Cardiovascular Medicine180Immunology142Pharmacology173Molecular Biology161Infectious Diseases150Rare and Inherited Diseases181Clinical Research173Anatomy and Physiology613Drugs and Chemicals621Psychiatry and Psychology185Public Health and Nutrition178Diagnostics and Medical Technology125Respiratory Medicine113Digestive System and Liver91Metabolism and Endocrine Disease177Bones, Joints, Muscles and Skin213Kidney, Urology and Women's Health173Eye, Ear, Nose and Throat55
Plans & pricingCompare EvidenceHelix workspace plans
Library›EvidenceLib›Kidney, Urology and Women's Health›Pyometra

Continue where you left off ()

Explore more with EvidenceHelix Workspace

Compare studies, analyze evidence and create research reports with premium tools.

Explore Researcher plans

Research reading room

Pyometra

Kidney, Urology and Women's Health · NLM MeSH · updated 2026-11-04 · version 1

Citations verified against PubMedNot yet clinician-reviewed10 referencesApproximately 6 min read

An accumulation of PUS in the uterine cavity (uterus).

Table of Contents

1. Definition2. Research landscape3. Reading the evidence4. Open-access studies5. Key reviews6. References7. About this article

Definition and research guide

This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.

Content available: 4 complete abstracts (1,106 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.

Definition

An accumulation of PUS in the uterine cavity (uterus). Pyometra generally indicates the presence of infections.

Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.

Also known as: Pyometras.

Where it fits in the MeSH classification

Broader topics
Uterine Diseases

Related concepts

  • Uterus

Research landscape

PubMed indexes 427 records tagged with the MeSH heading “Pyometra” (counts retrieved 2026-11-04). 162 of them (37.9%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 203 records.

Reviews account for 23 records (5.4%) and meta-analyses for 1. Randomized controlled trials number 3 (0.7%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.

PubMed records by publication periodthrough 1999: 38 records; 2000-2009: 24 records; 2010-2019: 203 records; 2020 onward: 162 records38through 1999242000-20092032010-20191622020 onward
Records in PubMed indexed with this heading, by publication period. Real counts from NCBI E-utilities; the final period covers only part of the current year. Volume reflects how much has been published, not how strong the evidence is.
Show the data
PeriodRecords
through 199938
2000-200924
2010-2019203
2020 onward162
Share of records by publication typeReviews: 5.4 percent; Meta-analyses: 0.2 percent; Randomized controlled trials: 0.7 percentReviews5.4% (23)Meta-analyses0.2% (1)Randomized controlled trials0.7% (3)
Share of all PubMed records on this heading that carry each publication type. Types overlap with other records, so the shares do not sum to 100%.
Publication-type chart data
Publication types among 427 PubMed records
TypeRecordsShare
Reviews235.4%
Meta-analyses10.2%
Randomized controlled trials30.7%

Method: PubMed query "Pyometra"[MeSH Terms] with publication-type and date filters, retrieved 2026-11-04.

Reading the evidence in kidney, urology and women's health

Kidney, urinary and reproductive health research uses lab markers (such as creatinine), imaging, symptom scores and registry data on pregnancy and birth. Findings about pregnancy are especially sensitive to who was studied and when in pregnancy exposure occurred. Nothing on this page is advice about treatment, fertility or pregnancy; speak to a qualified clinician. Check the population, the outcome measured and whether the study accounted for other health differences between groups.

Evidence from open-access studies

These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.

Study comparison — selected abstracts, not a systematic review
Study / authorsYearSource label / designEurope PMC citationsLicence / source
Outcome of pyometra in female dogs and predictors of peritonitis and prolonged postoperative hospitalization in surgically treated cases
Jitpean S, Ström-Holst B, Emanuelson U, Höglund OV, Pettersson A, Alneryd-Bull C, et al.
2014Research article
Design not recorded in structured metadata
43cc by
PMID 24393406 · DOI · PMC3892096
Blood lactate levels in 31 female dogs with pyometra
Hagman R, Reezigt BJ, Bergström Ledin H, Karlstam E
2009Research article
Design not recorded in structured metadata
25cc by
PMID 19134167 · DOI · PMC2630309
Closed cervix is associated with more severe illness in dogs with pyometra
Jitpean S, Ambrosen A, Emanuelson U, Hagman R
2017Research article
Design not recorded in structured metadata
23cc by
PMID 28056957 · DOI · PMC5217653
Multidrug resistance of bacterial pathogens in canine pyometra
Camozzi MGM, Waller SB, Castelhano EC, Neves ALS, Arrais BR, Pinto JFN, et al.
2026Research article
Design not recorded in structured metadata
1cc by
PMID 41834532 · DOI · PMC13327223

Outcome of pyometra in female dogs and predictors of peritonitis and prolonged postoperative hospitalization in surgically treated cases [1]

Research article Jitpean S, Ström-Holst B, Emanuelson U, Höglund OV, Pettersson A, Alneryd-Bull C, et al. · · 2014 · cited 43 times (Europe PMC)

Abstract reading summary — source excerpts
Opening excerpt
BackgroundOne of the most common diseases in intact bitches is pyometra--a potentially life-threatening disease associated with a variety of clinical and laboratory findings.
Closing excerpt
The results of the present study may be valuable for identifying peritonitis and predicting increased morbidity in surgically treated bitches with pyometra.
Interpretation limits
Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (275 words)

BackgroundOne of the most common diseases in intact bitches is pyometra--a potentially life-threatening disease associated with a variety of clinical and laboratory findings. The aims of the present study were to describe complications of the disease and to investigate clinically useful indicators associated with peritonitis and/or prolonged postoperative hospitalization.ResultsA retrospective study was performed using records from 356 bitches diagnosed with pyometra during the years 2006-2007 at the University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden. Of the 356 bitches, 315 were surgically treated by ovariohysterectomy, 9 were medically treated and 32 were euthanized without treatment. In the surgically treated bitches, univariable associations between clinical and laboratory data, risk for prolonged hospitalization (≥ 3 days) and/or signs of peritonitis, were analyzed by Chi-square and Fisher's exact test. Logistic regression models were used to assess multivariable associations.The most common complication observed in surgically treated bitches was peritonitis (40 bitches), followed by urinary tract infection (19 bitches), wound infection (8 bitches), uveitis (6 bitches), and cardiac arrhythmia (5 bitches). Leucopenia and fever/hypothermia were associated with increased risk for peritonitis (18-fold and three-fold, respectively). Moderate to severe depression of the general condition, pale mucous membranes and leucopenia were associated with increased risk (seven-fold, three-fold, and over three-point-five-fold, respectively) for prolonged postoperative hospitalization.ConclusionsSeveral clinically useful indicators were identified. Leucopenia was the most important marker, associated with 18-fold increased risk for peritonitis and an over three-point-five increased risk for prolonged hospitalization. Fever/hypothermia, depression and pale mucous membranes were associated with increased risk for peritonitis and/or prolonged hospitalization. The results of the present study may be valuable for identifying peritonitis and predicting increased morbidity in surgically treated bitches with pyometra.

Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 24393406 · DOI · PMC3892096

Blood lactate levels in 31 female dogs with pyometra [2]

Research article Hagman R, Reezigt BJ, Bergström Ledin H, Karlstam E · · 2009 · cited 25 times (Europe PMC)

Abstract reading summary — source excerpts
Opening excerpt
BackgroundCanine pyometra is a life-threatening disease common in countries where spaying of dogs is not routinely performed.
Closing excerpt
The value of a single and repeated lactate analysis in more severely affected cases remains to be determined.
Interpretation limits
Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (327 words)

BackgroundCanine pyometra is a life-threatening disease common in countries where spaying of dogs is not routinely performed. The disease is associated with endotoxemia, sepsis, systemic inflammatory response syndrome (SIRS) and a 3-4% mortality rate. Blood lactate analysis is clinically valuable in predicting prognosis and survival, evaluating tissue perfusion and treatment response in human and veterinary critical care settings. The aims of the present study were to investigate 1) the blood lactate levels of female dogs with pyometra by a hand-held analyser and 2) if these levels are related with the clinical status or other biochemical or hematological disorders.MethodsIn total 31 female dogs with pyometra admitted for surgical ovariohysterectomy and 16 healthy female control dogs were included in the present study. A complete physical examination including SIRS-status determination was performed. Blood samples for lactate concentrations, hematological and biochemical parameters, acid-base and blood gas analysis and other laboratory parameters were collected and subsequently analysed. The diagnosis pyometra was verified with histopathological examination of the uterus and ovaries. Increased hospitalisation length and presence of SIRS were used as indicators of outcome.ResultsIn the pyometra group the median blood lactate level was 1.6 mmol l(-1) (range 2.5 mmol l(-1)) was demonstrated in one female dog with pyometra (3%), and was not associated with longer hospitalisation or presence of SIRS. Lactate measurement was not indicative of peritonitis. None of the bitches died during or within two months of the hospital stay. The measurements of temperature, heart rate, respiratory rate, percentage bandforms of neutrophilic granulocytes, alpha2-globulins, creatinin, pvCO2, TCO2 and base excess showed significant differences between the SIRS positive and the SIRS negative pyometra cases.ConclusionIncreased blood lactate concentrations were demonstrated in 3% (1/31), and SIRS was present in 61% (19/31) of the female dogs with pyometra. Preoperative lactate levels were not related with presence of SIRS or prolonged hospitalisation. Lactate measurement was not indicative of peritonitis. The value of a single and repeated lactate analysis in more severely affected cases remains to be determined.

Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 19134167 · DOI · PMC2630309

Closed cervix is associated with more severe illness in dogs with pyometra [3]

Research article Jitpean S, Ambrosen A, Emanuelson U, Hagman R · · 2017 · cited 23 times (Europe PMC)

Abstract reading summary — source excerpts
Opening excerpt
BackgroundPyometra, a life-threatening bacterial infection of the uterus, is classified as open or closed depending on the functional patency of the cervix i.
Closing excerpt
These findings may be clinically valuable for optimizing monitoring and treatments in dogs with the disease.
Interpretation limits
Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (206 words)

BackgroundPyometra, a life-threatening bacterial infection of the uterus, is classified as open or closed depending on the functional patency of the cervix i.e. presence or absence of vaginal discharge. In closed cervix pyometra, pus and bacterial products accumulate in the uterus, which is thought to induce a more severe illness. The aim of this study was to investigate whether disease severity or outcome differed in dogs with open or closed cervix pyometra.ResultsProspectively collected data from 111 female dogs diagnosed with pyometra at the University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, intermittently during 2005-2012 was analyzed. Seventy-two dogs (65%) had open cervix, whereas 39 dogs (35%) had closed cervix. Differences between the two groups were explored by Wilcoxon Two Sample Test for continuous variables and Chi-square or Fisher's exact test for categorical variables. P ConclusionsIn dogs with closed cervix, sepsis was more common, the general physical condition more often moderately to severely depressed and leukocytosis, neutrophilia and monocytosis more frequently found. The results showed that closed cervix was associated with a more severe illness than open cervix at admission but not with poorer outcome as measured by postoperative hospitalization. These findings may be clinically valuable for optimizing monitoring and treatments in dogs with the disease.

Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 28056957 · DOI · PMC5217653

Multidrug resistance of bacterial pathogens in canine pyometra [4]

Research article Camozzi MGM, Waller SB, Castelhano EC, Neves ALS, Arrais BR, Pinto JFN, et al. · · 2026 · cited 1 times (Europe PMC)

Abstract reading summary — source excerpts
Opening excerpt
ObjectivesTo characterise multidrug antimicrobial resistance and pathogenicity profiles of bacteria isolated from different anatomical sites in bitches with pyometra, emphasising their clinical relevance for diagnosis and therapeutic decision-making in small animal practice.
Closing excerpt
Furthermore, the recovery of genetically related Escherichia coli isolates from intestinal and reproductive tract samples supports the intestinal microbiota as a relevant source of infection in affected bitches.
Interpretation limits
Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (298 words)

ObjectivesTo characterise multidrug antimicrobial resistance and pathogenicity profiles of bacteria isolated from different anatomical sites in bitches with pyometra, emphasising their clinical relevance for diagnosis and therapeutic decision-making in small animal practice.Materials and methodsBacteria were obtained from the faeces, urine, uterus and vagina of 23 dogs diagnosed with pyometra undergoing ovariohysterectomy. Antimicrobial resistance profiles were analysed for all identified isolates, together with phylogenetic classification of Escherichia coli and detection of virulence factor-encoding genes.ResultsBacterial isolates obtained from faecal, urinary, uterine and vaginal samples showed predominantly positive growth for Escherichia coli, followed by Staphylococcus spp., Klebsiella pneumoniae and Proteus spp. Among these isolates recovered from each anatomical site, multidrug-resistant bacteria - defined as resistance to three or more classes of antimicrobials - were identified across all bacterial genera, with frequencies of 37.7% among faecal isolates, 16.7% among urinary isolates, 44.5% among uterine isolates and 100% among vaginal isolates, except for Enterobacter spp. Among dogs positive for Escherichia coli (11/23), phylogroups A/C (30.9%) were the most prevalent, followed by D/E (16.9%), B2 (15.5%), B1 (12.7%), A (12.7%), C (8.5%) and U (2.8%). In 90% (10/11) of cases, Escherichia coli isolates recovered from faecal, vaginal and/or uterine samples belonged to the same clonal family, suggesting faecal contamination. Overall, 77.4% of Escherichia coli isolates of uterine origin were classified as resistant or multidrug-resistant, and 83.9% harboured one or more virulence factor-encoding genes (hlyA, uspA, papC and predominantly fimH). Phylogroup B2 was the only group in which all assessed virulence factors were simultaneously detected.Clinical significanceThe presence of multidrug-resistant bacteria across all genera isolated in cases of canine pyometra underscores the clinical importance of antimicrobial susceptibility testing. Furthermore, the recovery of genetically related Escherichia coli isolates from intestinal and reproductive tract samples supports the intestinal microbiota as a relevant source of infection in affected bitches.

Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41834532 · DOI · PMC13327223

Key reviews and meta-analyses

The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.

  • Research article Pyometra in Small Animals [5]
    Hagman R · Vet Clin North Am Small Anim Pract · 2018 · cited 70 times (Europe PMC)
  • Research article Medical treatment for pyometra in dogs [6]
    Fieni F, Topie E, Gogny A · Reprod Domest Anim · 2014 · cited 36 times (Europe PMC)
  • Research article Canine pyometra: What is new? [7]
    Hagman R · Reprod Domest Anim · 2017 · cited 32 times (Europe PMC)
  • Research article Pyometra in Small Animals 2.0 [8]
    Hagman R · Vet Clin North Am Small Anim Pract · 2022 · cited 27 times (Europe PMC)
  • Research article Clinical and molecular characteristics of pyometra in female dogs [9]
    Hagman R · Reprod Domest Anim · 2012 · cited 27 times (Europe PMC)
  • Research article Pyometra in the queen: To spay or not to spay? [10]
    Hollinshead F, Krekeler N · J Feline Med Surg · 2016 · cited 24 times (Europe PMC)

References

  1. Jitpean S, Ström-Holst B, Emanuelson U, Höglund OV, Pettersson A, Alneryd-Bull C, et al.. Outcome of pyometra in female dogs and predictors of peritonitis and prolonged postoperative hospitalization in surgically treated cases. . 2014. PMID 24393406 · DOI · PMC3892096
  2. Hagman R, Reezigt BJ, Bergström Ledin H, Karlstam E. Blood lactate levels in 31 female dogs with pyometra. . 2009. PMID 19134167 · DOI · PMC2630309
  3. Jitpean S, Ambrosen A, Emanuelson U, Hagman R. Closed cervix is associated with more severe illness in dogs with pyometra. . 2017. PMID 28056957 · DOI · PMC5217653
  4. Camozzi MGM, Waller SB, Castelhano EC, Neves ALS, Arrais BR, Pinto JFN, et al.. Multidrug resistance of bacterial pathogens in canine pyometra. . 2026. PMID 41834532 · DOI · PMC13327223
  5. Hagman R. Pyometra in Small Animals. Vet Clin North Am Small Anim Pract. 2018. PMID 29933767 · DOI
  6. Fieni F, Topie E, Gogny A. Medical treatment for pyometra in dogs. Reprod Domest Anim. 2014. PMID 24947858 · DOI
  7. Hagman R. Canine pyometra: What is new?. Reprod Domest Anim. 2017. PMID 27807901 · DOI
  8. Hagman R. Pyometra in Small Animals 2.0. Vet Clin North Am Small Anim Pract. 2022. PMID 35465903 · DOI
  9. Hagman R. Clinical and molecular characteristics of pyometra in female dogs. Reprod Domest Anim. 2012. PMID 23279529 · DOI
  10. Hollinshead F, Krekeler N. Pyometra in the queen: To spay or not to spay?. J Feline Med Surg. 2016. PMID 26733546 · DOI · PMC11148877

About this article

Sources
NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
Verification
Every reference was resolved against PubMed on 2026-11-04; title, year and DOI matched.
Review state
automated source verified; no human expert review has been recorded yet.
Version
1, last updated 2026-11-04.

See how EvidenceLib is built. Spotted an error? Email support@evidencehelix.com.

Evidence strength

EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.

Included with the Researcher plan

Reading every article stays free. This computed view is part of the paid plans.

See plans Sign in

Your notes

Notes and highlights stay in this browser only; they are not sent to EvidenceHelix.

Related research topics

  • Uterine RuptureKidney, Urology and Women's Health
  • Uterine PerforationKidney, Urology and Women's Health
  • Uterine ProlapseKidney, Urology and Women's Health
  • Endometrial HyperplasiaKidney, Urology and Women's Health
  • EndometriosisKidney, Urology and Women's Health
  • Uterine InversionKidney, Urology and Women's Health

All 73 articles in Kidney, Urology and Women's Health →

At a glance

427
PubMed records on this heading
38%
published since 2020
23
review articles
3
randomized trials
10
verified references below

Counts come from PubMed on 2026-11-04; they show how much has been written, not how strong the evidence is.

Related topics See all →

  • Uterine RuptureKidney, Urology and Women's Health
  • Uterine PerforationKidney, Urology and Women's Health
  • Uterine ProlapseKidney, Urology and Women's Health
  • Endometrial HyperplasiaKidney, Urology and Women's Health
  • EndometriosisKidney, Urology and Women's Health

My notes & annotations (0)

Nothing yet. Select text and press Highlight, or write a note in the Notes tab. Stored in this browser only.

Sources

  • NLM MeSH record ↗
  • PubMed search used ↗

EvidenceLib is a research-education resource, not medical advice. It does not diagnose, prescribe or recommend starting, stopping or changing any treatment. Talk to a qualified clinician about your own situation. Methods, sources and licences · Rights and removal requests · Legal · Support