Causes of abortion in Australia (2005-2012) – proportion of cases due to Equine Amnionitis and Foetal Loss (EAFL)

Carrick, Joan; Perkins, N. R.; Zalucki, Myron P.

doi:10.1016/j.jevs.2013.10.154

Cited by 7 publications

(5 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This proportion of cases attributed to UC pathologies is in line with the previous figures from Newmarket diagnostic laboratories, which range between 38.8% and 46.2%, showing no change in 20 years 2,7 . This is markedly more than the peer‐reviewed reports from Kentucky, USA, which attributed only 3.4% of their submitted losses up to 24 hours post parturition to UC pathologies and 22.6% reported in Australia 11,34 . The limitation of these studies, however, is the reporting of submitted case proportions as opposed to a population incidence report and a current lack of a clear definition of what defines UCT with vascular compromise.…”

Section: Discussionsupporting

confidence: 88%

Incidence and causes of pregnancy loss after Day 70 of gestation in Thoroughbreds

Roach

Foote

Smith

et al. 2020

Equine Veterinary Journal

View full text Add to dashboard Cite

Background Pregnancy loss after Day 70 of gestation manifests as abortion, stillbirth or perinatal death. While previous studies have reported the diagnoses of laboratory submissions, none have quantified the incidence and causes of abortions, stillbirths and perinatal mortality at a population level. Objectives To report the incidence and causes of pregnancy loss after Day 70 of gestation in a cohort of Thoroughbreds. Study design Retrospective cohort study. Methods Outcomes of Day 70 pregnancies were collected from eight Thoroughbred farms over the 2013‐2017 breeding seasons. Stud, veterinary and laboratory records were supplemented with publicly available data. Cause of loss was categorised using custom criteria. Results Data were collected on 3,586 pregnancies from 1,802 mares. The incidence risk of a pregnancy failing to produce a live foal at 24 hours post parturition was 7.3% (95% confidence interval (CI) 6.5‐8.2, equating to 7.3 cases per 100 Day‐70 pregnancies). The incidence of pregnancy loss between Day 70 and 300 of gestation, Day 301‐315 and stillbirth/perinatal death was 4.0% (95% CI 3.4‐4.7), 0.3% (95% CI 0.2‐0.6) and 1.4% (95% CI 1.1‐1.9) respectively. Of the pregnancy losses where tissue was available, 61.1% were submitted for post‐mortem examination. The incidence risk of loss due to umbilical cord‐related pathologies was 1.5% (95% CI 1.1‐1.9), 0.4% (95% CI 0.2‐0.6) for noninfectious placental disease and 0.3% (95% CI 0.2‐0.6) for both infectious placentitis and Equine Herpesvirus infection. No primary diagnosis was made in 11.2% of the cases which underwent full post‐mortem examination. Main limitations It was not possible to differentiate between intra‐partum stillbirth and early post‐partum death. Conclusion Pregnancy loss after Day 70 of gestation is a significant source of loss in the Thoroughbred with umbilical cord‐related pathologies being the most commonly diagnosed cause. Reporting the incidence of pregnancy loss at a population level with clear case definitions will allow for accurate global comparisons.

show abstract

Section: Discussionsupporting

confidence: 88%

Incidence and causes of pregnancy loss after Day 70 of gestation in Thoroughbreds

Roach

Foote

Smith

et al. 2020

Equine Veterinary Journal

View full text Add to dashboard Cite

show abstract

“…This condition was first recognized in the Hunter Valley (NSW, Australia) in 2004 (Perkins, ; Todhunter et al , ) and has since been described in the Australian eastern states of Queensland, New South Wales and Victoria (Cawdell‐Smith et al , ). It is the most common diagnosed cause of abortion in the thoroughbred breeding industry in New South Wales (Todhunter et al , ; Carrick et al , ). When pregnant mares ingest O. lunifer larvae or exuviae, setae penetrate the gut and migrate throughout the body, ultimately causing a range of outcomes including focal mucoid placentitis, compromised foals, abortion and perinatal death (Cawdell‐Smith et al , , ; Todhunter et al , , ).…”

Section: Area Of Setal Fields and Density Of True Setae On Larvae Andmentioning

confidence: 99%

The urticating setae of Ochrogaster lunifer, an Australian processionary caterpillar of veterinary importance

Perkins

Zalucki

Perkins

et al. 2015

Medical Vet Entomology

View full text Add to dashboard Cite

The bag-shelter moth, Ochrogaster lunifer Herrich-Schaffer (Lepidoptera: Notodontidae), is associated with a condition called equine amnionitis and fetal loss (EAFL) on horse farms in Australia. Setal fragments from O. lunifer larvae have been identified in the placentas of experimentally aborted fetuses and their dams, and in clinical abortions. The gregarious larvae build silken nests in which large numbers cohabit over spring, summer and autumn. The final instars disperse to pupation sites in the ground where they overwinter. Field-collected O. lunifer larvae, their nests and nearby soil were examined using light and electron microscopy to identify setae likely to cause EAFL and to determine where and how many were present. Microtrichia, barbed hairs and true setae were found on the exoskeletons of the larvae. True setae matching the majority of setal fragments described from equine tissue were found on third to eighth instar larvae or exuviae. The number of true setae increased with the age of the larva; eighth instars carried around 2.0-2.5 million true setae. The exuvia of the pre-pupal instar was incorporated into the pupal chamber. The major sources of setae are likely to be nests, dispersing pre-pupal larvae and their exuviae, and pupal chambers.

show abstract

“…The primary pathology relating to the UC in horses is abortion due to UC torsion (UCT) and vascular compromise, resulting in the loss of 1.5% of pregnancies in UK Thoroughbreds. 10 Umbilical cord torsions are associated with excessive length of the UC, 8,9,[11][12][13] therefore understanding the magnitude to which the length is increased, and mechanisms for UCL growth, is important. To date, there is no published data on the growth of the UC through gestation.…”

Section: Introductionmentioning

confidence: 99%

“…To date, there is no published data on the growth of the UC through gestation. Comparisons of the UCL from UCT abortions can be made with data from term placentas 1,5,6 and abortions arising from other causes 8,9,[11][12][13] ; however, these may not be accurate due to UCT abortions occurring earlier in gestation than other causes of abortion. 10,12,14 Using current imaging modalities, it is not feasible to create growth curves of the equine UCL therefore estimates of the association of UCL and gestational age should be utilised using the best available alternative methodology.…”

Section: Introductionmentioning

confidence: 99%

The equine umbilical cord in clinically healthy pregnancies

Lawson,

Verheyen,

Smith

et al. 2024

Equine Veterinary Journal

View full text Add to dashboard Cite

BackgroundExcessive umbilical cord length (UCL) is associated with equine pregnancy loss. However, a lack of UCL reference values makes it difficult to define excessive UCL. Further, factors associated with differences in UCL are poorly understood.ObjectivesTo (i) report the total, allantoic and amniotic UCL in healthy term pregnancies in Thoroughbreds, (ii) describe the relationship between gestational age and UCL, fetal weight and crown rump length (CRL) using clinically normal pregnancies (CNPs) from mares dying during gestation, and (iii) identify associations between UCL and maternal age and parity, paternal age, and fetal sex.Study designCross‐sectional.MethodsData including UCLs, fetal weight, CRL and maternal age, parity, paternal age and fetal sex were taken from CNPs from Thoroughbred mares dying during gestation (n = 32), and placentas from HTPs (n = 34) in England. Correlations were assessed using Spearman's rank with significant correlations estimated by locally weighted scatter plot smoothing (LOWESS). Regression plots were fitted to highly correlated variables to further assess and quantify relationships. Differences in UCL between categorical variables were assessed using Kruskall Wallis and Mann–Whitney U tests.ResultsThe median total, amniotic and allantoic HTP UCLs were 53.5 cm (interquartile range [IQR] 16), 29.5 cm (IQR 7) and 25.0 cm (IQR 8) respectively. Gestational age and amniotic UCL were moderately correlated (rho = 0.53, p = 0.04), with LOWESS estimating an exponential increase followed by plateauing at around Day 200. Nonlinear associations were observed between fetal weight and gestational age and CRL (adjusted r2 = 0.98 and 0.95 respectively). A linear association was observed between gestational age and CRL: predicted CRL = −17.60 + 0.38 × gestational age, p < 0.001.Main limitationsLimited availability of CNPs from mares dying during gestation. Estimated relationships can only approximate growth.ConclusionsThis study provides important UCL and fetal size reference values, which may aid in assessing abnormalities. For the first time, associations between UCL and gestational age have been described.

show abstract

Causes of abortion in Australia (2005-2012) – proportion of cases due to Equine Amnionitis and Foetal Loss (EAFL)

Cited by 7 publications

References 2 publications

Incidence and causes of pregnancy loss after Day 70 of gestation in Thoroughbreds

Incidence and causes of pregnancy loss after Day 70 of gestation in Thoroughbreds

The urticating setae of Ochrogaster lunifer, an Australian processionary caterpillar of veterinary importance

The equine umbilical cord in clinically healthy pregnancies

Contact Info

Product

Resources

About