Retained fetal membranes (RFM) is a common post-partum problem in mares for which the treatment is highly variable. The aim of this study was (i) to investigate the different treatments used by ...equine practitioners for RFM and (ii) to determine if there is a difference between treatments used by reproductive specialists and general equine practitioners. Information regarding treatment of RFM was sought from veterinary practitioners via a survey and this was compared to recommendations in the current literature. The survey was sent out to equine veterinarians and mixed practitioners with a high equine case load. Most treatments of RFM were in line with current recommendations, while some obsolete practices are still routinely performed by a small number of practitioners. Treatment recommendations for RFM have changed over the last few decades, but there are no universally accepted guidelines. The vast variety of treatments reported by practitioners in the present survey reflect this lack of guidance. More extensive research is needed in this area to establish evidence-based, uniformly agreed upon protocols.
Pyometra in the queen Hollinshead, Fiona; Krekeler, Natali
Journal of Feline Medicine and Surgery,
01/2016, Letnik:
18, Številka:
1
Book Review, Journal Article
Recenzirano
Practical relevance:
Pyometra is a commonly occurring uterine disease in cats that often leads to loss of breeding potential and, in some cases, can be life threatening. An increased incidence of ...cystic endometrial hyperplasia (CEH) and pyometra is seen with age. Most queens present with uterine lesions after 5–7 years of age (average 7.6 years, range 1–20 years). Clinical signs most commonly occur within 4 weeks of the onset of oestrus in queens that are either mated, spontaneously ovulate or are induced to ovulate (mechanical stimulation or hormone induction). The disease is most often observed in dioestrus.
Clinical challenges:
Queens with pyometra often go undiagnosed as there may be few or only very mild clinical signs and laboratory changes. For example, the classic sign of mucopurulent bloody vulvar discharge often goes unnoticed. Abdominal ultrasound is the best tool for diagnosis of pyometra and for monitoring response to therapy.
Patient group:
Classically, middle-aged/older nulliparous intact queens present with pyometra. However, so-called ‘stump pyometra’ can occur if ovarian tissue is left behind during ovariectomy or ovariohysterectomy (ovarian remnant syndrome). Queens treated with exogenous steroid hormones such as high doses of megestrol acetate or medroxyprogesterone acetate for oestrus prevention can also develop CEH and pyometra.
Evidence base:
There has been little published to date on CEH, endometritis and pyometra in the queen and most of the currently available information has been extrapolated from studies carried out in the bitch. The queen and the bitch have very different reproductive physiology; thus, further research and investigation into the precise aetiopathogenesis of these disease processes of the uterus in the queen is warranted.
Audience:
This review is aimed at clinicians working in small animal practice, especially those in countries where surgical sterilisation is not practised as commonly as in the United States, Canada or Australasia, and who will therefore see a greater proportion of intact queens.
Increased ambient temperatures has been identified to contribute to reproductive outcomes for several domesticated species, but its impact on equine reproduction has not been previously investigated. ...Therefore, this study aimed to examine the relationship between ambient climatic conditions, as measured by temperature-humidity index (THI) between day 7 and day 14 of gestation, and early embryonic loss (EEL) in recipient mares undergoing embryo transfer.
The study examined records from 834 embryo transfers at an equine breeding facility in Victoria, Australia. Early embryonic loss was defined as a negative transrectal ultrasound on day 14 of gestation after an embryo was transferred on day 7. Both maximum THI on the day of transfer (day 7) and mean THI between day 7 and day 14 were investigated for association with the outcome of EEL using multivariable logistic regression, controlling for confounders including embryo age and quality, recipient mare quality and embryo transfer quality.
EEL was observed in 21% of embryo transfers. A five-unit increase in maximum THI on the day of transfer was associated with an 18% increase in the odds of EEL (p = 0.01). Similarly, the odds of EEL increased by 25% for each five-unit increase in mean THI between day 7 and 14 (p = 0.003).
As both single and cumulative episodes of high THI were associated with increased EEL in embryo transfer mares from this equine breeding facility, further studies are warranted to identify similar effects in a broader population, establish causality and evaluate possible mitigation strategies in anticipation of heat waves.
•Heat stress reduces reproductive outcomes in mares.•High temperature at equine embryo transfer associated with early embryonic loss.•High temperature after embryo transfer associated with early embryonic loss.
Infectious endometritis is a major cause of infertility in the mare and inflicts major losses on the equine breeding industry. The ability of the mare to eliminate uterine infections has been studied ...intensively for decades; however, despite identification of several factors contributing to the multifactorial pathogenesis and improved treatment, infectious endometritis remains a significant problem in a subpopulation of broodmares. Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is one of the most commonly isolated pathogens from the uterus of mares, suffering from infectious endometritis. Its ability to cause chronic latent infection by residing deep within the endometrial tissue has previously been described. The aim of the present study was to correlate different mare risk factors to infectious endometritis and pregnancy rates in broodmares and to investigate whether clonal or genetically distinct S. zooepidemicus strains isolated from mares with endometritis were associated with mare risk factors and the outcome of insemination. Mares (N = 152) were examined after natural cover, and 20% (31 mares) had intrauterine fluid (IUF) accumulation. Fifty-five percent (16 of 29) of the mares with IUF had infectious endometritis, and S. zooepidemicus was isolated in 81% (13 of 16) of these mares. Significantly more resting mares had IUF compared with foaling mares, and the foaling mares had the highest prevalence of positive bacterial growth from the uterine swab. The per-cycle pregnancy rate for the study was 63%. Pregnancy rate was significantly negatively affected by increased age (>12 years) and increased parity (>4), and the lowest pregnancy rate was observed in resting mares compared with foaling, barren, and maiden mares. Up to four S. zooepidemicus isolates were selected from each mare with growth of S. zooepidemicus from the uterine swab sample and further characterized by pulsed-field gel electrophoresis. In total, S. zooepidemicus isolates from 18 mares were analyzed with pulsed-field gel electrophoresis. In 13 mares, the isolates selected from each mare showed a high genetic relatedness within each individual mare, whereas two genetically distinct strains were isolated in five mares. A clonal S. zooepidemicus infection was associated with increased age, high parity, and poor vulvar conformation. Mares with clonal infection had a low pregnancy rate (38%) compared with mares with two strains isolated (80%). In conclusion, the results indicate that clonal S. zooepidemicus endometritis is associated with increased age, parity, and poor vulvar conformation in the broodmare.
Currently, limited information on the microbiome (community of microorganisms) and its role in infertility in the equine uterus is available beyond the detection of specific pathogens in some ...subfertile mares. Given that less than 1% of environmental bacteria are cultivable on common media (Handelsman, J. 2004, Microbiol Mol Biol Rev 68, 669-685.), it is likely that these cultured species represent a minority of the resident population. The overarching objectives of this project were to i) identify the resident uterine microbiome in estrus ii) assess how this microbiome evolves over time and iii) compare traditional culture-dependent methods of assessing the presence of bacteria in the equine uterus with 16S rRNA sequencing. Uterine cytobrush and swab samples were collected from 157 maiden Thoroughbred mares aged 8 years or younger and 116 Thoroughbred barren mares aged 4 to 15 years at the first reproductive exam of the breeding season. A second sample was collected from mares that were not pregnant at the end of the season (n=23). Furthermore, 20 of the mares were sampled in three consecutive breeding seasons. All cytobrush samples were placed and stored in RNAlater and kept at -20° C until further processing. Uterine swabs were plated on sheep blood and MacConkey plates, incubated at 37° C in aerobic conditions and assessed for bacterial growth at 24, 48 and 72 hours. DNA was extracted from cytobrush samples using routine methods. The genomic DNArecovered was used as a template for PCR amplification of the V3–V4 variable region of the bacterial 16S rRNA gene. Amplicons were sequenced on the Illumina MiSeq platform. DNA sequencing data was then processed to assess the equine microbiome composition. The richness (number of bacterial species) and evenness (distribution of bacterial numbers) of bacterial genetic sequences was compared between maiden, barren and wet mares and correlated with reproductive success. The microbiome was highly dynamic and changed significantly between seasons within mares with a limited “core microbiome” being detected. In some mares, conventional culture techniques failed to identify known equine genital pathogens that were detected using 16S rRNA sequencing. While the richness and evenness of the microbiome was comparable in maiden, dry and wet mares, the overall bacterial abundance was higher in mares that were barren at the beginning of the season and failed to become pregnant during the season, when compared to successfully bred barren mares and all maiden mares. This was the first time the microbiome of the equine uterus was studied over several timepoints/seasons. Future studies could explore a prognostic test that allows prediction of fertility in barren mares.
This work was funded by AgriFutures Australia.
The steroid hormone environment in healthy horses seems to have a significant impact on the efficiency of their uterine immune response. The objective of this study was to characterize the changes in ...gene expression in the equine endometrium in response to the introduction of bacterial pathogens and the influence of steroid hormone concentrations on this expression.
Endometrial biopsies were collected from five horses before and 3 h after the inoculation of Escherichia coli once in oestrus (follicle >35 mm in diameter) and once in dioestrus (5 days after ovulation) and analysed using high-throughput RNA sequencing techniques (RNA-Seq).
Comparison between time points revealed that 2422 genes were expressed at significantly higher levels and 2191 genes at significantly lower levels 3 h post inoculation in oestrus in comparison to pre-inoculation levels. In dioestrus, the expression of 1476 genes was up-regulated and 383 genes were down-regulated post inoculation. Many immune related genes were found to be up-regulated after the introduction of E. coli. These include pathogen recognition receptors, particularly toll-like receptors TLR2 and 4 and NOD-like receptor NLRC5. In addition, several interleukins including IL1B, IL6, IL8 and IL1ra were significantly up-regulated. Genes for chemokines, including CCL 2, CXCL 6, 9, 10, 11 and 16 and those for antimicrobial peptides, including secretory phospholipase sPLA 2, lipocalin 2, lysozyme and equine β-defensin 1, as well as the gene for tissue inhibitor for metalloproteinases TIMP-1 were also up-regulated post inoculation.
The results of this study emphasize the complexity of an effective uterine immune response during acute endometritis and the tight balance between pro- and anti-inflammatory factors required for efficient elimination of bacteria. It is one of the first high-throughput analyses of the uterine inflammatory response in any species and several new potential targets for treatment of inflammatory diseases of the equine uterus have been identified.
Persistent mating-induced endometritis (PMIE) severely decreases fertility in horses. The aim of the present study was to evaluate differences between horses susceptible to PMIE and a control group ...in terms of the expression of selected immune response and effector genes, and the effects of oestrous cycle stage on this expression. Endometrial biopsies from 18 uterine samples of mares in the control group (eight in dioestrus, 10 in oestrus) and 16 PMIE-susceptible mares (four in dioestrus, 12 in oestrus) were analysed by quantitative real-time reverse transcription-polymerase chain reaction. Genes for pathogen recognition receptors Toll-like receptor 2 (TLR2) and NLR family CARD domain containing 5 (NLRC5), as well as tissue-specific inhibitor of metalloproteinase 1 (TIMP1), C-X-C motif chemokine ligand (CXCL) 9, CXCL10 and CXCL11 and uteroferrin were expressed at similar levels in the control group and in susceptible mares. Genes for C-C motif chemokine ligand 2 (CCL2) and the antimicrobial peptides secreted phospholipase A2 (sPLA2), lipocalin 2 and lactoferrin were all expressed at higher levels in susceptible compared with control mares. The expression of genes for the antimicrobial peptides equine β-defensin 1 (EBD1), lysozyme (LYZ) and secretory leukoprotease inhibitor (SLPI) was also higher in susceptible than control mares. The diagnostic sensitivity of assays for EBD1, LYZ and SLP1 gene expression to detect susceptibility to PMIE was estimated to be 100%, 94% and 100% respectively, with specificities of 83%, 78% and 78% respectively. When all three tests were positive, the specificity increased to 94%, with an overall sensitivity of 94%. The present study has yielded insights into pathophysiological changes in mares susceptible to PMIE and identified robust diagnostic markers (EBD1, LYZ and SLPI) for susceptibility to this disease.
Escherichia coli is one of the most common microbial pathogens of equine endometritis. Despite seemingly appropriate veterinary intervention, these infections can become chronic in some mares ...resulting in long-term infertility. The formation of bacterial biofilm within the uterus has become a recently theorized, yet unsubstantiated, explanation for unresponsive endometrial bacterial infections in mares. The objective of this study was to examine the biofilm-forming potential (BFP) of E. coli isolates collected from the female equine reproductive tract by using the crystal violet assay and scanning electron microscopy. Approximately 27% of isolates (35/130) demonstrated strong BFP, with 23% (19/81) and 33% (16/49) of uterine and clitoral fossa isolates, respectively, showing strong BFP. Scanning electron microscopy showed E. coli arranged in a community of cells surrounded by an extracellular matrix of polymeric substances. Our results have shown a large number of E. coli isolates display BFP. Our results strongly support the theory that biofilm formation may be an important cause of chronic endometrial infection.
•We evaluate biofilm formation of 130 equine reproductive tract E.coli.•We confirm biofilm formation using scanning electron microscopy.•In total, 34% of isolates showed moderate to strong biofilm formation in vitro.•Twenty-three percent of uterine and 33% of clitoral fossa isolates were classified as strong.•SEM showed a community of E. coli cells surrounded by EPS.
Infectious endometritis is a major cause of reduced pregnancy rates in horses. The objectives of this study were to establish a timeline of the innate immune response in the uterus of healthy horses ...and to investigate the oestrous cycle effect on this. Endometrial biopsies were collected from five horses before and at 3, 12, 24, 48 and 72 h after inoculation of Escherichia coli, once in oestrus and once in dioestrus. They were analysed by quantitative real-time PCR, microbiology and histology. Neutrophil numbers increased from very low levels in the absence of inflammation to severe neutrophilia 3 h after inoculation. The concentrations of mRNAs for Toll-like receptor (TLR)2, TLR4, NOD-like receptor NLRC5, tissue inhibitor of metallopeptidases 1 (TIMP1) and chemokines CCL2, CXCL9, CXCL10 and CXCL11 were all increased 3 h after inoculation of E. coli compared to levels detected prior to inoculation. Chemokine mRNA levels remained elevated for 48 h. Concentrations of mRNAs for the antimicrobial peptides equine β-defensin 1 (EBD1), lysozyme, secretory leukoprotease inhibitor (SLPI), lipocalin 2 (LCN2), lactoferrin and uteroferrin were increased between 3 and 12 h post inoculation. The gene for secreted phospholipase A
(sPLA
) was expressed constitutively. P19 uterocalin mRNA levels were higher in dioestrus than in oestrus over the first 24 h of inflammation. Neutrophils and many innate immune genes responded rapidly to the introduction of E. coli into the uterus, while the oestrous cycle stage had only a relatively minor effect on the response to E. coli. This study has delineated a useful model of innate immunity in infectious endometritis of healthy animals.
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