EAFL R&D History – June 2015
The origin (2004-2005)
Multiple abortions with similar and unusual presenting pathology were detected around the Hunter Valley region in Thoroughbred and Quarterhorse mares in 2004. A wide ranging investigation occurred with HVERC funding that involved private veterinary practitioners, state veterinary services, university researchers and private consultants, resulting in development of the name, a case definition and preliminary ideas about causes (Perkins, 2005; Todhunter et al., 2009). Exposure of pregnant mares to processionary caterpillars (Ochrogaster lunifer) was identified as a possible cause.
Initial experimental research (2006-2010)
A series of experimental studies were conducted at the Gatton UQ campus involving exposure of pregnant mares to processionary caterpillar material, funded by HVERC and RIRDC. This work led to two PhDs and multiple publications and confirmed that exposure of pregnant mares to processionary caterpillars (Ochrogaster lunifer) caused abortion with the same signs and pathology as was seen in natural cases (Cawdell-Smith and Bryden, 2009; Todhunter and Cawdell-Smith, 2010).
It is important to note that all the initial experimental work was done using only processionary caterpillars. There are other hairy caterpillars in the environment and while the growing body of evidence suggests that processionary caterpillars may be the major cause of EAFL, they may not be the only cause.
Key players in this early work (2004-2010) were Dr Mark Wylie, Dr Kristen Todhunter, Dr Deb Racklyeft, Dr Angela Begg, Dr Judy Cawdell-Smith, Dr Catherine Chicken, Dr James Gilkerson, Dr Gary Muscatella, Dr Nigel Perkins and Professor Wayne Bryden. The initial work was supported by the Hunter Valley Equine Research Centre (HVERC) and in particular through the efforts of Mr Bill Rose and Dr Bill Howey. Many others were also involved.
Development of on-farm risk management (2007-current)
Once research had established that processionary caterpillars were an important cause of EAFL, effort turned to developing risk management strategies for broodmare farm owners and managers. After initial difficulties in recognising and being able to find caterpillars and nest material, by 2011 the initial risk management strategies had been developed and implemented on many farms with consequent reductions in numbers of abortions due to EAFL.
Strategies were largely based on detection and removal of caterpillars and associated nest material from paddocks where pregnant mares were being kept. Inspections and removals were timed mainly from about December (when new egg masses could be detected) to about February-March. The risk to mares was estimated to begin about February-March and continue through to foaling. This strategy continues now – based on detection and removal of risk material before mare risk is high.
Key players in the development of field caterpillar detection and control strategies were Dr Nigel Perkins and Professor Myron Zalucki with support from HVERC and horse breeding operations in both NSW and QLD.
The road to ARC-linkage research (2012 – 2013)
Over time there was strong support to seek additional research funding to develop better risk management strategies, by studying caterpillars and how they behave in the environment and also by understanding whether caterpillars other than the processionary caterpillar might be involved in EAFL.
In 2012 a team led by Professor Myron Zalucki was awarded a University of Queensland research grant through the Collaboration and Industry Engagement Fund (CIEF). The CIEF project was intended to support the development of university-industry collaborative partnerships leading to an application for a larger, multi-year Australian Research Council (ARC) linkage grant. The CIEF grant led to field research in 2012 and 2013.
An ARC-linkage grant application was submitted in late 2012 and was unsuccessful despite receiving favourable review. The team continued to do field work with the remaining CIEF funds and the following year (late 2013), submitted a second ARC-linkage grant application. This grant was successful and the ARC-linkage project formally began in 2014.
The ARC-linkage project (2014-2017)
The ARC-linkage scheme aims to fund collaborative research and development involving university researchers and industry partners, to apply innovative R&D to address real world risks and problems. The ARC-linkage grant project is valued at just over $500,000 and is scheduled to run from 2014 to 2017.
The project summary from the ARC-linkage material states:
Equine Amnionitis and Foetal Loss (EAFL) accounts for about a third of mares aborting in thoroughbred horse studs in southern Queensland, New South Wales and Victoria. Previous studies have shown that processionary caterpillars and their irritating setae (hairs) can cause EAFL. This project aims to determine the likelihood that other caterpillar species are involved based on hair morphology and a surrogate model system. A full risk assessment of the exposure of mares to these hairs in situ will be undertaken, based on the ecology and biology of the species. Outcomes include a management strategy for EAFL-causing insects and a reduction of EAFL within the industry.
The ARC-linkage grant team is made up of UQ researchers led by Professor Myron Zalucki, and industry partners including HVERC (Mr Derek Field) and AusVet Animal Health Services.
The team has developed a work plan and has begun both field work and laboratory studies aligned with the project aims and objectives. The team has close links to the horse industry and findings and future work activities will be discussed with industry groups.
Cawdell-Smith AJ and Bryden WL. Equine amnionitis and foetal loss – the role of caterpillars. RIRDC Publication No 09/155, 2009.
Perkins NR. Equine Amnionitis and foetal loss (EAFL). Report to the Hunter Valley Equine Research Centre (HVERC), March 2005.
Todhunter KH and Cawdell-Smith AJ. Histopathology of mares aborting due to equine amnionitis and foetal loss – the role of caterpillars. RIRDC Publication No 10/206, 2010.
Todhunter KH, Perkins NR, Wylie RM, Chicken C, Blishen AJ, Racklyeft DJ, Muscatello G, Wilson MC, Adams PL, Gilkerson JR, Bryden WL and Begg AP. Equine Amnionitis and fetal loss: The case definition for an unrecognised cause of abortion in mares. Australian Veterinary Journal 87:35-38, 2009.