Pregnancy project expands to build picture of foetal foal loss

Thoroughbred industry stakeholders set to benefit from greater access to fully funded confidential post-mortems

Phase two of the Post-mortem of pregnancy loss in thoroughbred horses project is set to offer breeders and their staff valuable insights into the causes of equine pregnancy loss, allowing them to reduce the risk of avoidable foal deaths.

Each year, approximately 12,000 thoroughbred foals are born across Australia. Despite this figure, more than 5% of mares abort their pregnancies each season, resulting in financial loss to the mare owner and, in some cases, a health and safety risk to horses and humans.

In phase one of the project, researchers reviewed more than 450 laboratory reports and post-mortem material, and produced detailed visual atlases of the features of equine pregnancy loss (see page 30 of the Thoroughbred Horses Program 2023 RD&E Snapshot).

In this second phase, the AgriFutures Thoroughbred Horses Program is funding 250 post-mortems over two years (2022–2023), which has resulted in the project expanding to include three additional clinics. Veterinarians from across the three states are being trained to conduct foetal post-mortems using draft manuals, training methods and case definitions developed during phase one.

Identifying trends of pregnancy loss

The two-year project will allow for a nationwide approach to submitting and analysing foetal post-mortems, with the goal of building a confidential database of results. Over time, this data will be analysed to identify trends and causes of late-term abortions, leading to a better understanding of why mares lose their pregnancies.

Dr Joan Carrick has more than 30 years’ experience carrying out foetal post-mortems on foals and is an integral member of the highly experienced project team. According to Joan, there are multiple examples of where a rapid diagnosis following a foetal post-mortem could have prevented a multi-abortion event on single farm or within a localised region.

“Recent outbreaks include the equine amnionitis and foetal loss syndrome during 2004–2005 and equine chlamydiosis during 2016,” she said.

“In the case of the EAFL syndrome, post-mortems lead to the identification of the causal factor — caterpillars.

“Since implementing an intensive caterpillar control program during 2012, the risk has been eliminated and there have been no further pregnancy losses due to EAFL syndrome.”

Joan’s long-term goal is to reduce foetal foal loss by better understanding and managing avoidable risk factors.

“In time I hope all aborted foals can be assessed with a full post-mortem, so we can reduce foetal loss across the board,” she said.

Additional clinical capacity for 2023

During the 2022 foaling season, veterinarians in the Hunter Valley (NSW), Goulburn Valley (Victoria) and Darling Downs (Queensland) regions carried out 93 free post-mortems. Joan is keen to see this number grow during the 2023 season with three new clinics coming on board.

“In addition to the three clinics that participated last year, we have had Hunter Equine Centre (NSW), Bendigo Equine Hospital (Victoria) and Scenic Rim Veterinary Services (Queensland) sign up to the project,” she said.

This means in 2023, breeders across NSW, Queensland and Victoria will collectively have access to 125 fully funded confidential post mortems.

“It’s great to see interest in the project grow and each year we are seeing more engagement from breeders,” Joan said.

“Stud farms, owners and veterinarians can use the insights gained from this project to more effectively manage pregnant mares, ultimately reducing the risk of abortions and boosting the numbers of healthy foals born each season.”

A report on the post-mortem will be available within 48 hours of completion and laboratory results will be provided as soon as they are available. A final report with diagnosis and advice on how to prevent further losses will generally be available within two weeks. Veterinarians will communicate with participating breeders as results come in to update them.

The results from the project will be used to identify causes and trends of late-term pregnancy loss in Australia’s thoroughbred broodmare population.

All post-mortem details will remain strictly confidential and the data will not directly link any horse, farm or breeder. The only people with access to identifiable results are the mare owner and the veterinarian who carried out the post-mortem.

Click here to find out more about what is happening in the AgriFutures Thoroughbred Horses Program