Etiology and pathology of equine placentitis.
Abstract: Placentas from aborted, stillborn, and premature foals were examined during the 1988 and 1989 foaling seasons, and 236 of 954 (24.7%) had placentitis. Microorganisms associated with placentitis were isolated or demonstrated from 162 of 236 (68.6%) placentitis cases. Leptospira spp. and a nocardioform actinomycete were 2 important, newly emerging bacteria associated with equine placentitis. Major pathogens identified in decreasing order were Streptococcus zooepidemicus, Leptospira spp., Escherichia coli, a nocardioform actinomycete, fungi, Pseudomonas aeruginosa, Streptococcus equisimilis, Enterobacter agglomerans, Klebsiella pneumoniae, and alpha-hemolytic Streptococcus. Pathogens were not recovered in 64 cases (27.1%) and overgrowth by saprophytic bacteria was recorded in 10 cases (4.2%). Twenty-seven cases (16.6%) had mixed bacterial growth and 93 cases (57.4%) had bacteria cultured from both placenta and fetal organs. The majority of the placentitis cases caused by bacteria, with the exception of Leptospira spp. and the nocardioform actinomycete, occurred in 2 forms. One was acute, focal or diffuse; had an infiltration of neutrophils in the intervillous spaces or necrosis of chorionic villi; was associated with bacteremia; and frequently occurred in the placenta from fetuses expelled before or at midgestation. The other was observed from foals expelled at late gestation, was mostly chronic and focal or focally extensive, and occurred mostly at the cervical star area. Chronic placentitis was characterized by the presence of 1 or a combination of the following lesions: necrosis of chorionic villi, presence of eosinophilic amorphous material on the chorion, and infiltration of mononuclear inflammatory cells in the intervillous spaces, villous stroma, chorionic stroma, vascular layer, and allantois.(ABSTRACT TRUNCATED AT 250 WORDS)
Publication Date: 1993-01-01 PubMed ID: 8466982DOI: 10.1177/104063879300500113Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research article is about a study conducted during 1988 and 1989, examining the origins and disease progression of placentitis in horses, including the key pathogens identified, common characteristics and findings, and differences based upon gestational stage.
Objective of the Research
- The main goal of this study was to investigate the causes and nature of placentitis in aborted, stillborn, and premature foals during the 1988 and 1989 breeding seasons. This involved understanding the microorganisms linked to placentitis and outlining the primary diseases present, as well as tracking the differing appearances and effects of the condition based on the gestational period.
Key Findings
- The researchers discovered that placentitis occurred in 24.7 percent of the cases (236 out of 954). They further identified microorganisms linked to placentitis in 68.6 percent of the placentitis instances (162 out of 236).
- Two new bacteria associated with equine placentitis, namely Leptospira spp. and a nocardioform actinomycete, were discovered during this study.
- The major pathogens found include Streptococcus zooepidemicus, Leptospira spp., Escherichia coli, a nocardioform actinomycete, Pseudomonas aeruginosa, fungi, and others. However, in 27.1 percent of the cases, pathogens were not found.
Diversity in Appearance and Conditions
- The research highlights two types of appearance for placentitis cases arising from bacteria (with the exception of Leptospira spp. and the nocardioform actinomycete).
- One type is acute and associated with bacteremia, found either in localized or widespread form, often observed in fetuses expelled before or at mid-gestation.
- The other type, typically noted in foals expelled later in gestation, is chronic and often located at the cervical star area. It is characterized by necrosis of chorionic villi, presence of eosinophilic amorphous material on the chorion, and infiltration of various inflammatory cells.
Cite This Article
APA
Hong CB, Donahue JM, Giles RC, Petrites-Murphy MB, Poonacha KB, Roberts AW, Smith BJ, Tramontin RR, Tuttle PA, Swerczek TW.
(1993).
Etiology and pathology of equine placentitis.
J Vet Diagn Invest, 5(1), 56-63.
https://doi.org/10.1177/104063879300500113 Publication
Researcher Affiliations
- Livestock Disease Diagnostic Center, University of Kentucky, Lexington 40511.
MeSH Terms
- Abortion, Veterinary
- Allantois / microbiology
- Allantois / pathology
- Animals
- Bacteria / isolation & purification
- Bacterial Infections / pathology
- Bacterial Infections / veterinary
- Chorion / microbiology
- Chorion / pathology
- Female
- Fetal Death / veterinary
- Horse Diseases / etiology
- Horse Diseases / pathology
- Horses
- Inflammation
- Placenta / microbiology
- Placenta / pathology
- Placenta Diseases / etiology
- Placenta Diseases / pathology
- Placenta Diseases / veterinary
- Pregnancy
Citations
This article has been cited 21 times.- Fedorka CE, Ali HE, Troedsson MHT. Galectins in Equine Placental Disease. Vet Sci 2023 Mar 13;10(3).
- Lorenzi AS, Bonatelli ML, Chia MA, Peressim L, Quecine MC. Opposite Sides of Pantoea agglomerans and Its Associated Commercial Outlook. Microorganisms 2022 Oct 20;10(10).
- Holyoak GR, Premathilake HU, Lyman CC, Sones JL, Gunn A, Wieneke X, DeSilva U. The healthy equine uterus harbors a distinct core microbiome plus a rich and diverse microbiome that varies with geographical location. Sci Rep 2022 Aug 30;12(1):14790.
- Akter R, El-Hage CM, Sansom FM, Carrick J, Devlin JM, Legione AR. Metagenomic investigation of potential abortigenic pathogens in foetal tissues from Australian horses. BMC Genomics 2021 Oct 2;22(1):713.
- El-Sheikh Ali H, Loux SC, Kennedy L, Scoggin KE, Dini P, Fedorka CE, Kalbfleisch TS, Esteller-Vico A, Horohov DW, Erol E, Carter CN, Smith JL, Ball BA. Transcriptomic analysis of equine chorioallantois reveals immune networks and molecular mechanisms involved in nocardioform placentitis. Vet Res 2021 Jul 8;52(1):103.
- Alamaary M, Ali A. Abortion and uterine prolapse in a Thoroughbred mare with twin pregnancy: Clinical and laboratory findings and treatment approach. J Equine Sci 2020;31(4):95-99.
- Mitchell ARM, Delvescovo B, Tse M, Crouch EE, Cheong SH, Castillo JM, Felippe MJB, Ainsworth DM, de Amorim MD. Successful management of hydrallantois in a Standardbred mare at term resulting in the birth of a live foal. Can Vet J 2019 May;60(5):495-501.
- Pinho MD, Erol E, Ribeiro-Gonçalves B, Mendes CI, Carriço JA, Matos SC, Preziuso S, Luebke-Becker A, Wieler LH, Melo-Cristino J, Ramirez M. Beta-hemolytic Streptococcus dysgalactiae strains isolated from horses are a genetically distinct population within the Streptococcus dysgalactiae taxon. Sci Rep 2016 Aug 17;6:31736.
- Sprayberry KA. Ultrasonographic Examination of the Equine Neonate: Thorax and Abdomen. Vet Clin North Am Equine Pract 2015 Dec;31(3):515-43.
- Gilday R, Lewis D, Lohmann KL. Mastitis in a neonatal filly. Can Vet J 2015 Jan;56(1):63-5.
- Kinoshita Y, Niwa H, Katayama Y. Development of a loop-mediated isothermal amplification method for detecting Streptococcus equi subsp. zooepidemicus and analysis of its use with three simple methods of extracting DNA from equine respiratory tract specimens. J Vet Med Sci 2014 Sep;76(9):1271-5.
- Villano JS, Rong F, Cooper TK. Bacterial infections in Myd88-deficient mice. Comp Med 2014 Apr;64(2):110-4.
- Paillot R, Darby AC, Robinson C, Wright NL, Steward KF, Anderson E, Webb K, Holden MT, Efstratiou A, Broughton K, Jolley KA, Priestnall SL, Marotti Campi MC, Hughes MA, Radford A, Erles K, Waller AS. Identification of three novel superantigen-encoding genes in Streptococcus equi subsp. zooepidemicus, szeF, szeN, and szeP. Infect Immun 2010 Nov;78(11):4817-27.
- Preziuso S, Laus F, Tejeda AR, Valente C, Cuteri V. Detection of Streptococcus dysgalactiae subsp. equisimilis in equine nasopharyngeal swabs by PCR. J Vet Sci 2010 Mar;11(1):67-72.
- Lin YP, Lee DW, McDonough SP, Nicholson LK, Sharma Y, Chang YF. Repeated domains of leptospira immunoglobulin-like proteins interact with elastin and tropoelastin. J Biol Chem 2009 Jul 17;284(29):19380-91.
- Pınar O, Çelik Doğan C, Aktaran Bala D, Kumaş C, Mete A. Analysis of the presence of Beta-hemolytic streptococci and cytological profiles in horse tracheal lavage samples with diverse clinical respiratory symptoms. BMC Vet Res 2025 Oct 2;21(1):558.
- Hardefeldt L, Thomas K, Page S, Norris J, Browning G, El Hage C, Stewart A, Gilkerson J, Muscatello G, Verwilghen D, van Galen G, Bauquier J, Cuming R, Reynolds B, Whittaker C, Wilkes E, Clulow J, Burden C, Begg L. Antimicrobial prescribing guidelines for horses in Australia. Aust Vet J 2025 Dec;103(12):781-889.
- Marchio SP, El-Sheikh Ali H, Scott MA, Barbosa Fernandes C, Scoggin KE, Troedsson M, Boakari Y. Decoding the amniotic membrane transcriptome during equine ascending placentitis. Sci Rep 2025 Aug 21;15(1):30714.
- Holy O, Sladecek V, Bzdil J, Zouharova M, Parra-Flores J, Caneiras C. Unveiling the prevalence and antimicrobial resistance landscape of Pantoea genus in veterinary clinical strains: Insights from a cohort study. One Health 2025 Dec;21:101130.
- Morales-Vázquez MM, Meza-Serrano E, Lara-Pereyra I, Acuña-González RJ, Alonso-Morales R, Hayen-Valles S, Boeta AM, Zarco L, Lozano-Cuenca J, López-Canales JS, Flores-Herrera H. Equine Placentitis in Mares Induces the Secretion of Pro-Inflammatory Cytokine eIL-1β and the Active Extracellular Matrix Metalloproteinase (MMP)-9. Vet Sci 2023 Aug 22;10(9).
- Beckers KF, Gomes VCL, Crissman KR, Liu CC, Schulz CJ, Childers GW, Sones JL. Metagenetic Analysis of the Pregnant Microbiome in Horses. Animals (Basel) 2023 Jun 15;13(12).
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