Investigations into Causes of Equine Abortions and Perinatal Loss in Canada
Bibliographic record
Abstract
Around 20% of Equine Canada members surveyed identify themselves as horse breeders, making equine breeding a large component of the equestrian industry in Canada. Major sources of economic loss for horse breeders are equine abortion and early foal death, as both outcomes result in a wasted breeding year for the broodmare. However, investigations into causes of abortion and foal death in Canada are few. Our initial retrospective studies examined the most common causes of abortion and early foal loss across Canada, drawing on necropsy reports from the large provincial diagnostic labs. From these studies, we identified that umbilical cord torsions were very common in Canada, similar to findings out of the United Kingdom. In neonatal foals, noninfectious diseases as a group were more common than infectious diseases, however overall the most common cause of loss was bacterial infections, including septicemia. Looking into bacterial infections and abortions in horses identified a potential knowledge gap, as recent investigations into Chlamydia as a cause of equine abortion in Australia created questions regarding whether Chlamydia was a potential abortigenic agent in North America. We pursued this knowledge gap through performing PCR on archived formalin-fixed, paraffin-embedded equine chorioallantois tissues, and identified 22 PCR-positive cases of Chlamydia in 99 samples. We continued this research by investigating equine endometrial biopsies, identifying 40 PCR-positive cases in 98 samples. These findings collectively suggest that Chlamydia, specifically Chlamydia abortus, may have a significant role in equine abortion and infertility in Western Canada. Finally, we examined the potential role of umbilical cord torsions, the most common cause of abortion in Canada, in early neonatal health. Using data collected through social media from around the world, we identified that foals with longer umbilical cords or more twists in their umbilical cords had a higher risk of abnormal neonatal health outcomes, such as being slow to meet typical milestones. Affected foals were also more likely to require medical intervention at birth and more likely to develop an internal medicine-related condition between birth and 7 days of age. Overall, these studies provide additional insight into equine abortions and early foal loss, with an emphasis on these conditions in a Canadian context.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.005 | 0.005 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".