Project snapshot: Phase 3 of case control study of mid-late term pregnancy loss in Thoroughbred mares
Mare pregnancy loss in NSW and QLD Thoroughbreds: explore causes, risks and management to improve foal outcomes and productivity.
THOROUGHBRED HORSES
Project snapshot: Phase 3 of case control study of mid-late term pregnancy loss in Thoroughbred mares
4 pages
Published: 26 Jun 2026
Author(s): Carrick, J., Brookes, V.
Share this content
-
Download report PDF
Download
This report examines mid-to-late pregnancy loss in Thoroughbred mares and its impact on productivity and profitability in the Australian breeding industry.
The study focuses on farms in New South Wales and Queensland and explores incidence, timing, causes and risk factors. Average pregnancy loss rates remained below 8% in both states. However, results varied by region and farm, ranging from 0% to 13%, with greater variation in Queensland.
Older mares showed a higher risk of pregnancy loss, with affected mares averaging one year older than those that maintained pregnancy. Most losses occurred before 270 days of gestation. Many cases were not investigated, which limited understanding of the underlying causes. The findings highlight the need for more consistent investigation practices across farms.
Environmental conditions played an important role. Better paddock quality and infrastructure were linked to lower pregnancy loss rates. In New South Wales, mares that aborted were less likely to have received Salmonella vaccination. This link requires further research to confirm its role in reducing losses.
The report provides clear guidance for breeding operations. It supports improved investigation of pregnancy loss, better paddock management and informed decision-making about mare age. It also identifies the need for further research on vaccination.
Adoption of these strategies can reduce losses, increase live foal numbers and improve overall industry productivity.
Related resources
Project overview: Thoroughbred Breeding Industry Workforce Strategy
Australia’s thoroughbred breeding industry faces labour shortages, unclear career pathways and training gaps. This project overview outlines a practical workforce strategy to improve skills, retention...
Equine fetal post-mortem guidelines for veterinarians
Around 5% of Thoroughbred mares in Australia lose their pregnancies each year, resulting in significant welfare, environmental and economic impacts across the Thoroughbred industry. These...
Project snapshot: Understanding a Recessive Embryo-Lethal Genotype in Australian Thoroughbred Horses
This report explores a common genetic issue linked to early pregnancy loss in Australian Thoroughbred horses. It explains how better understanding this risk can help...
Project snapshot: Genomic insights into multi-drug resistant Salmonella in Australian Thoroughbreds
Genomic insights into multi-drug resistant Salmonella in Australian Thoroughbreds is a research project investigating the genetic makeup of Salmonella strains affecting Thoroughbred horses in Australia....
Pocket guide: Best practice internal parasite management in Australian Thoroughbred horses - A veterinarian’s guide
This pocket guide will assist veterinarians working with Thoroughbred horses to: Advise clients on best practice internal parasite management which aligns with current research Understand...
Pocket guide: Winning against worms - An industry guide to best practice internal parasite management in Australian Thoroughbred horses
This pocket guide provides evidence-based, best practice approaches in an Australian context. It is designed to help stud owners, farm managers and staff: Reduce worm...
Project overview: Using Behavioural Science to Enhance Extension and Adoption Outcomes in the Thoroughbred Horse Industry
This project addresses a critical gap between high‑quality research and real‑world practice by identifying the social, attitudinal and contextual factors that influence adoption. Through a...