RIRDC Completed Projects in 2001-2002 and Research in Progress as at June 2002

Sub-Program 3.5

HORSES

June 2002 RIRDC Publication No 02/074

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© 2002 Rural Industries Research and Development Corporation. All rights reserved. ISBN 0 642 584737 7 ISSN 1440 6845 "RIRDC Completed Projects in 2001-02 and Research in Progress as at June 2002 - 3.5 Horses Publication No 02/074 The views expressed and the conclusions reached in this publication are those of the author and not necessarily those of persons consulted. RIRDC shall not be responsible in any way whatsoever to any person who relies in whole or in part on the contents of this report. This publication is copyright. However, RIRDC encourages wide dissemination of its research, providing the Corporation is clearly acknowledged. For any other enquiries concerning reproduction, contact the Publications Manager on phone 02 6272 3186. RIRDC Horses Research Manager Dr John Freestone RIRDC Level 1, AMA House 42 Macquarie Street BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: 02 6576 4200 Fax: 02 6576 4020 Email: john.freestone@rirdc.gov.au RIRDC Publications Manager Cecile Ferguson Rural Industries Research and Development Corporation Level 1, AMA House 42 Macquarie Street BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: 02 6272 3186 Fax: 02 6272 5877 Email: cecilef@rirdc.gov.au Website: http://www.rirdc.gov.au

Published in June 2002 Printed on environmentally friendly paper by Canprint

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Foreword

This year RIRDC has produced Research in Progress, June '02, which contains short summaries of continuing projects as well as those that were completed during 2001-02 for all of the Corporation’s 20 program areas. The complete report on all the programs is only available in electronic format on our website at http://www.rirdc.gov.au The following report is a hardcopy extract covering Sub-Program 3.5. It contains all entries from continuing and completed horse research projects funded by RIRDC. Our horse program aims to assist in developing the Australian horse industry and enhancing its export potential. This report is the newest addition to our extensive catalogue of almost 800 research reports, videos and CD-Roms of projects supported by RIRDC. Please contact us for the latest publications catalogue or view it on our website: • downloads at www.rirdc.gov.au/reports/Index.htm • purchases at www.rirdc.gov.au/eshop Peter Core Managing Director Rural Industries Research and Development Corporation

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Contents

3.5 HORSES COMPLETED PROJECTS

PROJECT

No PROJECT TITLE RESEARCHER PHONE ORGANISATION PAGE No

1. Information Technology for the Horse Industry US-101A International Horse Industry Symposium Dr William Howey (02) 9351 7971 The University of Sydney

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2. Industry Development and Development of Equine Research Infrastructure in Australia US-102A Racecourse Managers Research Planning

Workshop

Ms Shirley Ray (02) 9352 6932 The University of Sydney

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US-103A Production of a manual of equine exotic disease for the horse owner

Dr Jennifer Hodgson (02) 4655 0745 The University of Sydney 8

3. Respiratory Diseases-Improving the Respiratory Health of Horses UMA-15A Improved vaccine strategies for management of

equine herpesvirus diseases

A/Prof Millar Whalley A/Prof Daria Love

(02) 9850 8200 (02) 9351 2454

Macquarie University The University of Sydney

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UMU-25A Role of equine herpesvirus type 2 and 5 in respiratory disease

A/Prof Graham Wilcox (08) 9360 2448 Murdoch University

5. Lameness and Limb Injury-Developing More Effective Methods for Prevention, Diagnosis and Treatment UF-7A Monitoring Falls During Eventing — A pilot project to

determine the feasibility of monitoring horse and rider fall-related injuries during the cross-country phase of eventing

Dr Raymond Cripps (08) 8374 0970 Flinders University of South Australia

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UMU-24A Investigation into radiographic changes in the carpus (C3) in racehorses

Dr Catherine Steel (08) 9360 2356 Murdoch University 15

UQ-71A Novel anti-inflammatory drugs to treat inflammatory diseases in horses

Dr Stephen Taylor (07) 3365 3124 The University of Queensland 17

UQ-75A The pathogenesis and prevention of equine laminitis Dr Christopher Pollitt (07) 3365 2063 The University of Queensland

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8. Improving Racetracks and Working Surfaces for Horses PTP-17A 6th Australian racecourse manager's conference –

2001

Mr Arthur Stubbs (03) 9844 1135 Primary Tasks Pty Ltd 19

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3.5 HORSES

RESEARCH IN PROGRESS

PROJECT No

PROJECT TITLE RESEARCHER PHONE ORGANISATION PAGE No

1. Information Technology for the Horse Industry US-95A Communication and Information Programs for the

Horse Industry

Ms Shirley Ray (02) 9352 6932 The University of Sydney 20

3. Respiratory Diseases-Improving the Respiratory Health of Horses UM-47A Effects of stud management on ecology of virulent

Rhodococcus equine

Dr Glenn Browning (03) 9344 7342 The University of Melbourne 21

UMU-28A Role of latent equine herpesvirus infections in respiratory disease

A/Prof Graham Wilcox (08) 9360 2448 Murdoch University 22

US-82A A Longitudinal Cohort Study of Inflammatory Airway Disease in Racing Thoroughbreds

Dr Jennifer Hodgson (02) 4655 0745 The University of Sydney 23

US-83A An epidemiological study of ‘tying up’ in athletic horses

A/Prof. David Hodgson (02) 4655 0777 The University of Sydney 24

US-96A Investigations of Equine Herpesvirus 1 cycle of infection in foals

A/Prof Daria Love (02) 9351 2454 The University of Sydney 25

US-108A Prospective Longitudinal Study of disease on Equine Stud Farms

Dr. James Gilkerson (02) 6545 1607 The University of Sydney 26

4. Nutrition Research-Development Better Ways to Feed Horses DAV-187A Objective measurement of fodder quality across

animal species

Mr. Peter Flinn (03) 5573 0915 Department of Natural Resources & Environment (Vic)

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ULA-14A Glucose synthesis in equine hepatocytes

Dr. Theresa Frankel (03) 9479 2180 La Trobe University 28

UQ-72A Nutritent intake and growth of young horses

Dr Neil McMeniman (07) 3365 1108 The University of Queensland 29

5. Lameness and Limb Injury-Developing More Effective Methods for Prevention, Diagnosis and Treatment UQ-100A Pasture fructan concentration as a cause of equine

laminitis

Dr Christopher Pollitt (07) 3365 2063 The University of Queensland 30

US-84A An epidemiological study of risk factors for shin soreness in Thoroughbred racehorses

Dr David Evans (02) 9351 2474 The University of Sydney 31

7. Reducing Reproductive Failure in Mares and Stallions and Establishing More Effective Treatments for Diseases of Foals IMV-4A Further development of vaccines against

rhodococcus equi infection in foals

A/Prof. Mary Barton (08) 8302 2933 Institute of Medical & Veterinary Science

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UMA-17A Evaluating equine immune responses to new EHV-1 vaccine candidates

A/Prof. Millar Whalley (02) 9850 8200

Macquarie University

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UMO-26A Analysis of horse breeding efficiency in Australia

Dr Angus McKinnon (03) 5829 9566 Goulburn Valley Equine Hospital 34

9. Other EVA-1A 2002 Bain-Fallon Conference (Gold Coast)

Dr. James Gilkerson (02) 6545 1607 Australian Equine Veterinary

Association 35

UNE-78A Scholarship - Nerida McGilchrist

Ms. Nerida McGilchrist (02) 6773 5135 University of New England 36

US-113A Scholarship - Sundrela Kamhieh

Ms. Sundrela Kamhieh University of Sydney 37

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3.5 HORSES

COMPLETED PROJECTS

1. Information Technology for the Horse Industry Project Title:

The International Horse Industry Symposium

RIRDC Project No.:

US-101A

Researcher: Dr Bill Howey Organisation: PostGraduate Foundation in Veterinary Science

Level 2, Conference Centre Building 22 Regimental Cres. University NSW 2006

Phone: 029351 7979 Fax: 029351 7968 Email: howeywp@pgf.edu.au

Objectives • The presentation of the latest information in research and development in the horse

industry • Enhancement of the interchange between researchers and the horse industry • Dissemination of informed veterinary opinion to the discerning horse owning public • The establishment of a synergistic collaborative post graduate network of equine

research scientists

Background The Post Graduate Foundation in Veterinary Science is an organisation committed to the mission of continuing veterinary education and enhanced professional development for veterinary graduates, equine research scientists and the horse industry.

Research A 3 day seminar coordinated by the Post Graduate Foundation in Veterinary Science incorporating days for research presentations and streamed delivery of informed opinion to various horse industry sectors was held at the University of Sydney. Two highly skilled and internationally recognised key speakers, Dr Peter Rossdale and Professor Leo Jeffcott presented papers on research in general as well as their particular areas of interest. Attendees came from all sectors of the horse industry.

Outcomes The symposium provided an effective arena for the communication of the latest advances in the areas of Molecular and Advanced Technologies, Growth and Development, Nutrition and disease to all areas of the horse industry. Presentations by postgraduate students undertaking equine research were outstanding and it was generally agreed that the future of equine research in Australia is looking very good.

Implications Discussions during day 1 of the symposium, focussing on the draft RIRDC 5-Year Plan for Equine Research suggested that a comprehensive range of research areas be included to encourage current researchers to continue their research interests.

Publications “International Horse Industry Symposium” proceedings available from the University of Sydney Post Graduate Foundation in Veterinary Science.

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2. Industry Development and Development of Equine Research Infrastructure in Australia Project Title:

Racecourse R&D Workshop

RIRDC Project No.:

US-102A

Researcher: Shirley Ray Organisation: University of Sydney Phone: 02 9351 6932 Fax: 02 9351 3056 Email: shirleyr@camden.usyd.edu.au

Objectives • understand the key R&D issues relating to racetrack maintenance upgrade and

design • link racecourse managers with researchers • develop clear priorities for R&D projects that will provide outcomes for the racing

industry

Background The workshop was the outcome of a short forum on research and development priorities for racecourse management, held at the 5th Racecourse Manager’s Conference in Melbourne in June 2000. A follow-up workshop was then proposed to discuss options and implementation of research and development.

Research Seventeen people were invited to attend the workshop, including four involved with racecourse management, five associated with turf and track surface research, three veterinarians working on horse performance a racecourse design engineer and four members of the RIRDC Equine R&D committee. Two syndicate groups discussed and reported on the current relevance of various issues and priorities for racecourse R&D followed by possible projects, including objectives, methodology and benefits.

Outcomes The Workshop produced outlines for two similar R&D projects, both connected with collection and collation of data that provides objective measurements of track shape, surface maintenance and use and the relationship of that data to horse injury, durability and performance. Racecourse R&D priorities were listed for comment and rating by participants for future attention.

Implications The involvement of racing industry stakeholders in these projects will be important pooling of knowledge and capabilities and joint “ownership” of the R&D work and results. The benefits of the proposed projects will include: definition of recommended track construction and maintenance practices for safe and consistent training and racing and identification of parameters for prediction of horse performance and injury.

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Project Title:

Equine Exotic Diseases. A Manual for Horse Owners

RIRDC Project No.:

US 103A

Researcher: Dr Jennifer Hodgson Organisation: University of Sydney Phone: (02) 4655 0760 Fax: (02) 4655 1212 Email: jennih@camden.usyd.edu.au

Objectives Australia is in the privileged position of being free of many of the serious infectious

diseases of horses that are found elsewhere in the world. However, in this era of increasing globalisation and international movement of horses, the risk for the introduction of an exotic disease to our equine population is increasing. The purpose of this manual is to increase awareness within the horse community of the exotic diseases that may affect horses and outline the ways that horse owners can play a role in preventing their introduction.

Background Exotic or foreign diseases are those diseases caused by infectious organisms (viruses, bacteria, fungi or parasites) that are not usually present in Australia, but may be introduced either temporarily or permanently. If a serious exotic disease were to be to be introduced to our horse population, the effects could be tremendous and would be felt by all members of the equine community. Not only would there be economic losses associated with the outbreak of a serious exotic disease, but the potential loss of horse’s lives must also be a consideration. In order to prevent this from occurring we need knowledgeable horse men and women who are aware of these diseases, know how to help prevent their introduction, and what they should do if they suspect an exotic disease has been introduced.

Research The book entitled “Equine Exotic Diseases – A Manual for Horses Owners” provides the Australian horse owner with information about exotic diseases of horses. The manual first presents some background facts and figures on the exotic equine diseases such as how they may enter Australia, how they may spread around Australia, and the risk factors that can influence the likelihood of their introduction. Interviews with horse people are included, and offer viewpoints on the significance of exotic diseases for the Australian equine industry. The specific exotic diseases are then discussed, with emphasis on how the horse may appear (clinical signs). In this way horse owners can be alert to these signs and can notify the appropriate authorities should they notice anything unusual. The manual also provides information on what a horse owner should do if they suspect an exotic horse disease and what precautions they should take to help prevent their introduction.

Outcomes Everyone in the horse industry has a role to play in preventing an outbreak of an exotic disease. By increasing our knowledge of these diseases we can more effectively ensure that we fulfil this role. Maintenance of Australia’s disease-free status for these serious equine infections is the desired end result. The benefits of this outcome for our horse owners, horse industry and equine export industry are clear.

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3. Respiratory Diseases-Improving the Respiratory Health of Horses Project Title:

Improved Vaccine Strategies for Management of Equine Herpesvirus Diseases

RIRDC Project No.: UMA-15A Researcher: Associate Professors J. M. Whalley & D. N. Love Organisation: Macquarie University University of Sydney Phone: 02 9850 8200 Fax: 02 9850 8245 Email: mwhalley@rna.bio.mq.edu.au

Objectives Objectives: Consistent with the RIRDC Five-Year Plan, the overall objectives were to

improve reproductive efficiency and respiratory health in horse populations by reduction of incidence of herpesvirus abortion and respiratory infection. Specifically, the project aimed: a) to obtain updated epidemiological information on incidence of equine herpesviruses 1 (EHV-1) and equine herpesvirus 4 (EHV-4) in populations of horses that had been vaccinated, and b) to assess the effectiveness and use of different types of vaccines for EHV-1 and EHV-4.

Background EHV-1 continues to be a cause world-wide of epidemic abortion, perinatal mortality, respiratory disease and occasionally neurological signs in horses. Prior to 1997 in Australia, we described a silent cycle of infection by EHV-1 (and EHV-4) in unvaccinated horse populations. This project examined the effect of vaccination on this cycle. In addition a new EHV-1 subunit vaccine was compared with other vaccine strategies including a whole virus vaccine.

Research Epidemiology: The seroepidemiological and DNA data indicated that EHV-1 infection and spread were continuing to occur from 1998 - 2000. Therefore, although the current vaccine can elicit immune responses in a percentage of horses, the cycle of EHV-1 (and EHV-4) infection continues in the vaccinated population in a similar manner to unvaccinated horses. Vaccines: Response to vaccination in the field. This study measured antibody responses to vaccination of 159 mares and 101 foals on a large stud farm with a whole virus EHV-1/4 vaccine. 29% of mares, and 47% of foals were classed as responding to vaccination. 17% of mares were classified as persistently seropositive. In general both mares and foals with higher antibody levels had poor reponses to vaccination. Comparison of vaccines Over 90% of adult horses showed a strong antibody response to a new subunit vaccine. Although only a single antigen, the subunit vaccine generated comparable antibody responses to the whole virus vaccine.

Outcomes • Information that EHV-1 continues to circulate between mares and foals in vaccinated stud farm populations

• A recombinant subunit protein gD of EHV-1 elicits strong antiviral immune responses against EHV-1 (and EHV-4), confirming this antigen as an excellent vaccine candidate that has the potential to replace whole virus vaccines.

Implications The continued presence of EHV-1 (and EHV-4) in vaccinated populations means that

careful management practices need to be maintained. Knowledge of antibody status may allow a more selective vaccination strategy, representing considerable savings. New approaches to vaccination are required, possibly based on subunit vaccines, which can be manipulated to optimize protective immune responses.

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Publications • Gilkerson, J. R., Whalley, J. M., Drummer, H. E., Studdert, M. J. & Love, D. N. (1999).

Epidemiological studies of EHV-1 in Thoroughbred foals: a review of studies conducted in the Hunter Valley of New South Wales between 1995 and 1997. Veterinary Microbiology 68, 15-25.

• Ruitenberg, K. M., Love, D. N., Gilkerson, J. R., Wellington, J. E. & Whalley, J. M. (2000). EHV-1 glycoprotein D DNA inoculation in horses with pre-existing EHV-1/EHV-4 antibody. Veterinary Microbiology 76, 117-127.

• Gilkerson, J. R., Love, D. N. & Whalley, J. M. (2000). Incidence of equine herpesvirus 1 infection in Thoroughbred weanlings on two stud farms. Australian Veterinary Journal 78, 277-278.

• Foote, C. E., Love, D. N., Gilkerson, J. R., & Whalley, J. M. (2002). Serological responses of mares and weanlings following vaccination with an inactivated whole virus EHV-1 and EHV-4 vaccine Veterinary Microbiology (in press)

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Project Title:

Role of equine herpesvirus types 2 and 5 in respiratory disease

RIRDC Project No.: UMU-25A Researcher: Prof Graham Wilcox Dr Sharanne Raidal Organisation: School of Veterinary Biology and Biomedical Sciences

Division of Veterinary and Biomedical Sciences Murdoch University

Phone: 08 9360 2448 Fax: 08 9310 4144 Email: wilcox@numbat.murdoch.edu.au sharanne@numbat.murdoch.edu.au

Objectives • to provide evidence that some strains of EHV2 are causes of respiratory disease,

perhaps acting as stressors activating other latent equine herpesviruses. • this is a pilot project to assess the importance of EHV2 as a potential pathogen prior

to undertaking a more complete project to assess the role of latency of EHV2 and other herpesviruses in the persistence and pathogenesis of these virus infections.

Background Previous studies (RIRDC publication No 00/146) demonstrated a high prevalence of

EHV in horses not showing evidence of respiratory disease. In the absence of clinical signs, it was assumed that the virus detected may have been latent. Improved technologies, able to discriminate latent (inactive) virus from active infection, are required so that the contribution of latent virus infection to clinical disease can be determined. We have also produced evidence linking EHV2, possibly in association with EHV4, with respiratory disease in young horses. Further studies are required to clarify the significance of EHV2, and the recently recognised EHV5, as pathogens in horses.

Research Epidemiological study to detect equine herpesviruses associated with respiratory disease in young horses: NS and peripheral blood samples were obtained from weaned and unweaned foals at 7 Thoroughbred (n=119) and 5 Standardbred studs (n=49). Serial samples were obtained from foals on seven properties. Samples were collected from additional Thoroughbred (n=43) and Standardbred (n=30) yearlings. Experimental infection of horses with EHV2: Mixed breed yearling horses (14) were experimentally infected with EHV2 isolated from horses with respiratory disease (n=8) or served as uninfected controls (n=6).

Outcomes EHV2 was detected in samples collected from 29 foals with respiratory disease on two studs. Serial sampling demonstrated that EHV2 was not detected after resolution of disease. Re-sampling of horses, where possible, prior to and/or after yearling sales in February/March 2001showed that EHV2 was uncommonly identified in samples from healthy horses, but major outbreaks of respiratory were not observed in this cohort of horses at these times. EHV5 was commonly identified in NS and peripheral blood samples from unweaned, weaned and yearling horses. Infection with EHV2 was difficult to achieve in the experimental horses, requiring large doses of infectious virus in sedated horses (unsedated horses appeared to be able to rapidly clear the viral inoculum). Clinical signs of serous or mucoid nasal and/or ocular discharge were associated with transient shedding of EHV2 from infected horses. The EHV2-induced disease was self-limiting with complete recovery within 10 – 14 days. Over the course of the study, shedding of EHV2 and EHV4 was observed in uninfected horses, associated with clinical signs of mild respiratory disease, and was assumed to be due to the activation of latent virus.

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Implications Our results indicate that EHV5 is very common in young horses, that primary infection

occurs prior to weaning and that EHV5 infection appears to persist in young horses. We have not yet determined if EHV5 infection is associated with the detection of actively replicating or latent virus. This will be determined during the continuing project on latent equine herpesvirus infections in the horse (UMU-28A) EHV2, in contrast to EHV5, was less commonly isolated from young horses, and its presence was associated with the occurrence of mild respiratory disease in young horses.

Publications The results obtained during this pilot study will be presented in part during a talk by Wilcox GE on “Latent Equine herpesvirus infection” at the July 2001 Horse Industry Symposium, Sydney. Papers that are now being sent for publication are: A nested multiplex PCR for the detection and differentiation of equine herpes virus 1, 2, 4 and 5, by Liping Wang, Sharanne Raidal and Graham E. Wilcox. An association between equine herpesvirus 2 (EHV2) and respiratory disease in young horses, by Liping Wang, A Pizzirani, GE Wilcox and Sharanne Raidal.

• The association of equine herpesviruses (EHV) with respiratory disease and poor performance in adult horses in Western Australia, by Liping Wang, GE Wilcox, CM Steel and SL Raidal.

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5. Lameness and Limb Injury-Developing More Effective Methods for Prevention, Diagnosis and Treatment Project Title:

Monitoring Falls During Eventing — A pilot project to determine the feasibility of monitoring horse and rider fall-related injuries during the cross-country phase of eventing

RIRDC Project No.:

UF-7A

Researcher: Raymond A. Cripps Organisation: Flinders University

Research Centre for Injury Studies Bedford Park SA 5158

Phone: 08 8374 0970 Fax: 08 8374 0702 Email: Ray.cripps@nisu.flinders.edu.au

Objectives To see if monitoring of falls and injuries to horse and riders during the cross-country phase

of eventing in NSW and SA is feasible.

Background In Australia, no monitoring of falls and injuries to horse and riders currently occur. A recent marked increase in the number of rider deaths associated with the sport of eventing (both in Australia and overseas) has focused attention on rider safety. At the same time, the number of claims made on the EFA’s national member accident insurance policy has also highlighted the relatively high cost of injuries incurred in activities associated with horses. There has been no collection of data on the health, social or financial costs of such injuries. If the equestrian community is to develop policies for prevention and management of these injuries, and their associated costs, accurate data is needed on which to base the policy development, and any strategic directions for equestrian associations and interested medical/health bodies.

Research A process to collect information on the event, riders and falls was set up in NSW and SA and data was collected during the 2001 eventing season. Several data collection instruments (Falls Report Form and a Questionnaire) were developed and refined and used to collect data for the study. One hundred and seventy-two falls occurred with some riders having more than one fall during the eventing season. The results indicated that the rate of falls was low in NSW and SA (1.4 and 2.4 falls per 1000 jumping efforts, respectively). However, the rate of falls increased as the level of competition increased from Pre-novice to Advanced classes. Twenty-eight per cent of the riders who fell reported injuries from falling. Injury to the upper body was reported in two-thirds of the injured riders. Most injuries were minor, but eleven went to the Emergency Department for treatment and eight were admitted to hospital. Head injuries and fractures were treated in hospital.

Outcomes The pilot demonstrated that monitoring of falls during the cross-country phase of eventing was feasible and the information collected was suitable for a surveillance system and of high value. As a result of this pilot project, a national surveillance system to monitor falls and their injuries will be set up in all states and will collect horse and riders’ fall data during the 2002 and 2003 eventing season.

Implications The implementation of a national surveillance system to monitor falls in Australia is a world first. It supports the safety initiatives of the Fédération Equestre Internationale (FEI) and Equestrian Federation of Australia (EFA). The data obtained will support a program of research on injury prevention and the development of counter-measures to reduce falls and injuries during eventing

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Publications Cripps RA, Pagano H, O’Brien D 2002. Feasibility of establishing a national surveillance

program to monitor falls during eventing in Australia: A pilot study. RIRDC funded project, in progress. Cripps RA, Steenkamp M, Harrison JH 2002. Injury hospital morbidity, Australia 1998–99. Injury Research and Statistics Series. Adelaide: AIHW, in press Steenkamp M & Cripps RA 2001. Child injuries due to falls. Injury Research and Statistics Series. Adelaide: Australian Institute of Health and Welfare (AIHW cat no. INJCAT 37). Cripps RA & Carman J 2001. Falls by the elderly in Australia: Trends and data for 1998. Injury Research and Statistics Series. Adelaide: Australian Institute of Health and Welfare (AIHW cat no. INJCAT 35). Cripps RA. Horse-related injury in Australia. Australian Injury Prevention Bulletin 24, AIHW Cat. No. INJ26, May 2000. Research Centre for Injury Studies, Flinders University, 2000. O’Connor P & Cripps R 1999. Traumatic brain injury (TBI) surveillance issues: a discussion paper. Canberra: Australian Institute of Health and Welfare. O’Connor P, Bordeaux S, Cripps R 1999. Assembly of statistical information on road crashes and road injury in rural and remote areas of South Australia. Adelaide: Flinders University, Research Centre for Injury Studies. Cripps RA, O'Connor PJ. 1998. Spinal Cord Injury, Australia 1996/97. Australian Injury Prevention Bulletin 18, AIHW Cat. No. INJ013, April. Adelaide: Research Centre for Injury Studies, Flinders University of South Australia. Harrison J & Cripps R 1994. Injury in Australia: an epidemiological review. Canberra: Commonwealth Department of Human Services and Health.

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Project Title:

Investigation into radiographic changes in the carpus (C3) in racehorses

RIRDC Project No.:

UMU-24A

Researcher: Dr CM (Kate) Steel, Dr Belinda Hopper, Dr Jennifer Richardson, Dr Guy Alexander, and Assoc. Prof. Ian Robertson.

Organisation: Division of Veterinary and Biomedical Sciences Murdoch University South Street Murdoch WA 6150

Phone: 08 9360 2356 Fax: 08 9310 7495 Email: csteel@central.murdoch.edu.au; jennyr@numbat.murdoch.edu.au;

blgwynne@numbat.murdoch.edu.au

Objectives • The main objectives of this research were: • To develop a protocol that can be readily applied by veterinarians for describing

exercise-induced radiographic changes (sclerosis) in the third carpal bone (C3) • To determine the clinical significance of these changes, and in doing so develop a

better understanding of the role of C3 sclerosis in carpal lameness in young Standardbred racehorses.

• To identify predisposing factors for carpal lameness in these horses • To determine the effect of carpal lameness on the prognosis for racing success in

young Standardbred racehorses • To evaluate the effect of rest, reduced training, and continued race training on

clinical and radiographic findings and outcome in horses that developed carpal lameness with C3 sclerosis

• To determine the extent of C3 pathology that may be overlooked on routine radiographs by comparing radiographic and CT images from horses

Background Although the importance of C3 sclerosis as a cause of lameness has been recognized, there is an incomplete understanding of many aspects of this condition. A large-scale prospective clinical study of the radiographic development of C3 sclerosis and other carpal lesions over time has not been reported. An improved understanding of the significance of radiographic changes in C3 would permit more strategic training of horses and assist clinicians in interpreting carpal radiographs, predicting the onset of joint disease, and in making recommendations for the management of affected horses.

Research 114 Standardbred horses, all pacers, were examined for lameness and had radiographs taken of both carpi throughout the first 12-18 months of race training. In the first part of the study, we described the radiographic changes that occurred in C3 with race training, determined the clinical significance of various radiographic changes in C3, and defined the extent of sclerosis that may be considered a normal exercise-induced adaptive change, and that which is inappropriate for various stages of training and associated with carpal lameness. In the second part of the study we determined the importance of carpal lameness as a cause of wastage in these horses, described the clinical findings associated with carpal lameness due to C3 sclerosis, and investigated the potential for age at onset of training, conformation, and type of training to act as predisposing factors for carpal lameness. In addition, we determined the effect of C3 sclerosis as a cause of lameness on the prognosis for racing success, and evaluated the effect of rest, reduced training, and continued race training on the clinical findings and outcome in horses that developed carpal lameness. In the third part of the study, we described the computed tomography (CT) appearance of C3 and determined the usefulness of radiography in demonstrating the extent of bone pathology by comparing the radiographic and CT images from 19 Thoroughbred horses with various exercise histories.

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Outcomes We established that carpal lameness is common in Standardbred horses in their first year

of training and racing. It is an important cause of lost training days, and can result in reduced performance and premature retirement. Intercarpal joint lameness developed in 28% of 114 horses, and was diagnosed in 56% of cases of forelimb lameness. Lameness that responded to intercarpal joint anaesthesia, in the absence of other radiographic signs of joint disease, was attributed to C3 sclerosis in most horses. Results of scintigraphic examination of a limited number of horses lent support to this assumption. In Chapter 1 of this study, a system of obtaining skyline views that were repeatable and of sufficient quality for diagnosis was described and a new protocol for describing subchondral bone sclerosis and associated radiographic changes in C3 was developed that can be readily applied by veterinarians in practice. We identified that two radiographic parameters, the maximum trabecular score and the area of the radial facet affected by sclerosis (% total sclerosis), were most useful for correlating sclerosis with lameness and performance, and these formed the basis of the new grading guidelines. A continuous increase in C3 radiographic sclerosis with time in young Standardbred horses in race training was evident. Once horses had commenced racing, the parameters of trabecular score and % total sclerosis were useful indicators and predictors of lameness due to C3 sclerosis. There was a highly significant difference in incidence of lameness between horses with mild sclerosis (0%) and severe sclerosis (43%). However, the finding that some horses with severe sclerosis remained sound throughout the study highlights the need for other diagnostic imaging techniques to distinguish pathological C3 sclerosis. We concluded that horses with severe C3 sclerosis are more likely to be lame and may have less athletic potential than horses with lesser radiographic changes, however, C3 sclerosis and carpal lameness does not necessarily preclude a horse from having a successful racing career. We also concluded that radiography is useful in diagnosis but that a combination of diagnostic tests may be required to interpret the clinical significance of findings and confirm the diagnosis. Poor conformation was identified as a risk factor that may predispose individual horses to carpal lameness, but the age of horses when they started training, and training regime were not found to be risk factors, however, further investigation of the effect of training regime is warranted. Our findings indicated that carpal lameness may develop at any stage of training. Diligent observation of young horses for lameness from the onset of training is therefore indicated. Further investigation as to why some horses suffer unusually drastic effects of light exercise is warranted. Rest was unlikely to result in a favourable outcome if lameness was associated with severe sclerosis and further evaluation of modified training as a management option for lameness associated with C3 sclerosis is needed. In general, there was a good correlation between the findings on CT images and radiographs in respect to sclerosis parameters, however, CT allowed identification of some lesions not apparent on radiographs.

Implications Carpal lameness is an important cause of wastage in young Standardbreds in race training. We have developed an improved means of describing and interpreting the significance of radiographic changes in C3 and have an improved understanding of the role of C3 sclerosis and associated changes in carpal lameness.

Publications There are no publications to date but a series of papers will be published in an appropriate veterinary journal

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Project Title:

Novel anti-inflammatory drugs to treat inflammatory diseases in horses

RIRDC Project No.:

UQ 71A

Researcher: I. Shiels and S. Taylor Organisation: University of Queensland

St Lucia QLD 4072 Phone: (07) 33653124 Fax: (07) 33651766 Email: S.Taylor@mailbox.uq.edu.au

Objectives The project endeavored to determine the potential therapeutic value for horses of 2 novel

antiinflammatory drugs and to identify diseases, which would provide therapeutic targets for the agents. The project also compared the efficacy of the new agents with a number of drugs that are currently used to treat horses, or are considered to be the most effective agents for the treatment of inflammatory diseases in humans.

Background Inflammation is a universal process that can affect every organ system in the body. Some forms of inflammation are life threatening, like that which accompanies some forms of colic, or can cause permanent change in the function of the organ, as seen in chronic arthritis. The drugs currently available are not totally effective at controlling acute severe inflammation or reducing the damage caused by chronic inflammation. New antiinflammatory drugs are being developed to address some of the limitations of current drugs - like side effects and efficacy.

Research The study evaluated 2 drugs in models of colic and arthritis and compared them with a number of aspirin-like drugs currently used in the clinic. These diseases were selected because current treatments do not significantly reduce the severity of the condition (colic) or prevent the structural damage, which accompanies the disease (arthritis).

Outcomes One drug, an inhibitor of the inflammatory mediator C5a, was a potent inhibitor of inflammation in both disease models. The other drug, an inhibitor of an enzyme that is involved in the synthesis of a number of inflammatory mediators, had less efficacy, but performed better than the current therapeutic substances. The aspirin-like drugs performed poorly.

Implications These drugs could be developed for veterinary use if further clinical testing is undertaken.

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Project Title:

The pathogenesis and prevention of equine laminitis

RIRDC Project No.:

UQ-75A

Researcher: Chris Pollitt Organisation: School of Veterinary Science

The University of Queensland St Lucia Qld 4072.

Phone: 07 3365 2063 Fax: 07 3365 1899 Email: c.pollitt@mailbox.uq.edu.au

Objectives • Objective 1. Determine the role and control the activity of matrix

metalloproteinases (MMPs) in the pathogenesis of laminitis so that a product can be developed that will prevent and treat the disease.

• Objective 2. Determine the role of changes in the pattern of glucose metabolism in the pathogenesis of laminitis as a basis for predicting and preventing laminitis.

Background The key lesion of equine laminitis is failure of the connective tissue attachment apparatus that normally suspends the distal phalanx from the epidermal lamellae of the inner hoof wall. The aim of this project was to conduct research that would elucidate the pathogenesis of laminitis and ultimately lead to effective, rational prevention and treatment strategies.

Research The nature of MMP enzymes that normally reshape the continually growing hoof wall was established. In laminitis, increased amounts of MMPs are produced and this leads to destruction of the attachments between bone and hoof. The attachments are fine ultrastructural filaments that activated MMPs target and destroy. Substances generated by hindgut bacteria activate lamellar MMPs and reach the feet via a dilated circulation. Limiting the amount of glucose available to lamellar hoof also destroys attachments between hoof and bone but by a different mechanism; the disappearance of small, discrete attachment discs called hemidesmosomes. The rate of hemidesmosme disappearance and loss of attachment filaments correlates with dose of carbohydrate alimentary overload

Outcomes Methods to inhibit lamellar MMP enzymes have the potential to block the onset of laminitis and should be developed. Identification and purification of the bacterial laminitis trigger factors will lead to antidotes that could also block laminitis development. Laminitis trigger factors escape from the hindgut and reach the feet via the circulation. Limb cryotherapy effectively shuts down the circulation and should also be tried as a laminitis preventive. Since the severity of laminitis correlates with dose of carbohydrate in the hindgut, measures to manage carbohydrate intake of horses both in stables and at pasture, need investigating.

Implications The new knowledge generated by this project, about the pathogenesis of laminitis, lays a foundation for the development of effective, new preventive and treatment strategies.

Publications Mungall, B.A., Kyaw-Tanner, M. & Pollitt.C.C. (2001). In vitro evidence for a bacterial pathogenesis of equine laminitis. Vet. Microbiol. 2070: 1-15 Mungall, B.A & Pollitt, C.C. (2001). Thermolysin Activates Equine Lamellar Hoof Matrix Metalloproteinases. J. comp. Pathol. (in press) Kyaw-Tanner, M., Mungall, B. A. & Pollitt C. C. (2001). Equine laminitis: matrix metalloproteinase-2 is up-regulated in the acute phase. Equine vet. J (in press).

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8. Improving Racetracks and Working Surfaces for Horses Project Title:

6th Australian Racecourse Managers’ Conference, 2001

RIRDC Project No.:

PTP-17A

Researcher: Arthur Stubbs David McLaren Organisation: Primary Tasks Pty Ltd Turfgrass Technology Pty Ltd

Unit 58, Level 2 9 George Street 247 Drummond Street Sandringham Vic 3191 Carlton Vic 3053

Phone: 03 9844 1135 03 9521 6982 Fax: 03 9844 4554 03 9521 6946 Email: akstubbs@compuserve.com mclaren@turftech.com.au

Objectives Improvement of inter-club communication and education on issues of racetrack care and

maintenance for the development of effective, overall strategies for racecourse management.

Background A survey of grass racecourses in Australia in 1995, funded by RIRDC, found a wide variation in the level of racecourse management expertise and technical knowledge. In addition, there was a sense of isolation by many racecourse managers and an expressed need for more information relevant to their jobs. This led to Racecourse Managers’ Conferences being held in subsequent years, at Rosehill, Moonee Valley, Doomben, Morphettville, Melbourne, and from August 13-15, 2001, the 6th Australian Racecourse Managers’ Conference, held at Randwick.

Outcomes More than 120 people attended the conference, including 85 racecourse managers, supervisors and staff from throughout Australia and New Zealand, plus suppliers and consultants to the racecourse industry, research workers and turf specialists. The objective was achieved through delivery and discussion of technical papers relevant to racecourses, racecourse R & D developments, an industry forum on track conditions, inspections of racecourses, and general liaison between racecourse managers, turf researchers, supppliers and specialists. Delegates recommended that a similar forum be organised in Perth in 2002. A Racecourse Managers Conference Committee was formalised to review ideas and make future plans.

Implications The conference will result in increased ability of racecourse managers’ to practise their profession and apply best practices, leading to higher standards of racecourse management. Benefits accrue from improvements in track performance, appearance and life, and associated economic and environmental advantages for racing clubs and the community. The conference also strengthened the resolve of racecourse managers to apply the accepted best practices, modified according to their particular situation, and armed them with the knowledge to justify their actions to the many stakeholders in the racing industry.

Publications 6th Australian Racecourse Managers’ Conference Proceedings, August, 2001.

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3.5 HORSES

RESEARCH IN PROGRESS

1. Information Technology for the Horse Industry Project Title

Communication and Information Programs for the Horse Industry

RIRDC Project No.:

US-95A

Start Date: 01/07/00 Finish Date: 01/07/03 Researcher: Ms. Shirley Ray Organisation: The University of Sydney

Faculty of Veterinary Science J D Stewart Building SYDNEY NSW 2006

Phone: (02) 9352 6932 Fax: (02) 9351 3056 Email: shirleyr@camden.usyd.edu.au

Objectives • To achieve widespread dissemination and use of R&D information by the

horse industry by: • Ongoing Development of a Database of Equine Organisation (locally and

internationally). To communicate with key industry groups. • RIRDC Equine Research News. This newsletter of 8 pages, published

quarterly, will provide the industry with information on topical research from around the world as well as updates on current RIRDC funded projects, interviews with research workers, workshops and invited reviews.

• RIRDC Internet Web Site. An Internet web site for the RIRDC Horse Program which will include links for online purchase of RIRDC publications, download of the RIRDC equine Research News, search facility for past issues and a subscription facility to receive the RIRDC Equine Research News via the Internet.

Current Progress

Four issues of the Equine Research News were produced during the last year. Each newsletter had a print run of 10,000 copies, all of which were distributed to various sectors of the horse industry. The newsletters contained summaries of articles of local and international interest, announcements of new RIRDC funded projects and updates of all currently funded projects and items of general interest to the horse industry. Articles from the newsletters have been reprinted in many local and international publications including: The Horse (USA), Hoofs and Horns, Australasian Equestrian and Hoofbeats. The RIRDC Equine Research Program Web site has been updated with the production of each newsletter. The site has links to relevant pages of the RIRDC web site, and at least 45 websites contain a link to the RIRDC Equine Program website. All past issues of the newsletter are available for download in PDF format which can be viewed using Adobe Acrobat. The site has recorded 29,665 hits. The mailing list for RIRDC Equine Research Program is updated regularly and contains contact details of Australian Horse Associations, Research Institutions and Personnel and Horse Publications. The most recent update added approximately 500 addresses and this was the result of interest generated in the Horse Program at Equitana.

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3. Respiratory Diseases-Improving the Respiratory Health of Horses Project Title

Effects of stud management on ecology of virulent Rhodococcus equine

RIRDC Project No.:

UM-47A

Start Date: 01/01/00 Finish Date: 31/12/02 Researcher: Dr. Glenn Browning Organisation: The University of Melbourne

Veterinary Preclinical Centre PARKVILLE VIC 3052

Phone: (03) 8344 7342 Fax: (03) 8344 7374 Email: glenfb@unimelb.edu.au

Objectives • Improve understanding of the ecology of virulent strains of Rhodococcus

equi • Identify factors in horse studs which may result in increased amounts of

virulent R. equi in the air inhaled by foals • Develop management strategies for reducing the airborne population of R

equi, thus reducing both the amount and severity of rattles and leading to improved responses to treatment

Current Progress

Analyses of virulent R. equi concentrations in the air and soil of stud farms in Victoria and in the Hunter Valley have been completed and preliminary conclusions on these data have been reported to participating farms and veterinarians. The results suggest that lane ways and holding pens are particularly dangerous areas on studs, but that some surfaces may significantly reduce this danger. Further analysis during the current stud season is being planned. Other studies have shown that infected foals expire high concentrations of virulent R. equi and that foal to foal spread may be significant. Further analysis, potentially in collaboration with the Irish Equine Centre, is being planned for the coming season.

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Project Title

Role of latent equine herpesvirus infections in respiratory disease

RIRDC Project No.:

UMU-28A

Start Date: 14/08/01 Finish Date: 20/06/04 Researcher: Prof. Graham Wilcox Organisation: Murdoch University

School of Veterinary Biology and Biomedical Sciences Division of Veterinary and Biomedical Sciences MURDOCH WA 6150

Phone: (08) 9360 2448 Fax: (08) 9310 4144 Email: wilcox@numbat.murdoch.edu.au

Objectives • Methods of differentiating latent and active herpesvirus infection, thus

enabling interpretation of the significance of herpesviruses detected in horses with respiratory disease, by 2002.

• Determination of factors that affect the activation of latent virus infections, and whether activation of latent virus infections contributes to the development of respiratory disease or decreased performance, by 2004.

• Evidence of whether some strains of EHV2 are causes of respiratory disease, perhaps acting as stressors activating other latent equine herpesviruses, by 2004.

Current Progress

We are developing methods of differentiating latent and actively replicating equine herpesvirus infection in clinical samples. A polymerase chain reaction (PCR) and a reverse transcription PCR has been utilized to detect viral DNA and mRNA respectively, against a structural protein of EHV1, EHV4, EHV2 and EHV5 in cell culture and blood cells from horses. We have assumed that the detection of both RNA and DNA in samples suggests active viral replication, whereas detection of viral DNA alone suggests the virus is latent. As the project is focused on the role of EHV2 and EHV5 in respiratory disease, we are also attempting detect latency associated transcripts of EHV2 and EHV5 as an additional method of confirming latency. We applied some of these techniques to 5 foals infected with EHV1 and found that the EHV1 infection was associated with reactivation and shedding of EHV2 approximately 5 to 7 days following primary EHV1 infection. We subsequently re-examined these foals to determine whether the stress of weaning would reactivate latent EHV infections in them; weaning did not appear to reactivate virus. To further our studies of EHV2 previously detected in several foals with respiratory disease, we attempted to determine if the EHV2 isolates were the same or perhaps the result of reactivation of latent viruses; there was 93-95% DNA homology in the gH region of the genome of these isolates compared to a reference EHV2strain, and 98-100% homology between the isolates from the outbreak, suggesting a single strain of EHV2 was responsible for the respiratory disease observed.

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Project Title

A Longitudinal Cohort Study of Inflammatory Airway Disease in Racing Thoroughbreds

RIRDC Project No.:

US-82A

Start Date: 26/07/99 Finish Date: 31/07/03 Researcher: Dr. Jennifer Hodgson Organisation: The University of Sydney

University Veterinary Centre Camden Department of Veterinary Clinical Sciences PMB 4, Narellan Delivery Centre NARELLAN NSW 2567

Phone: (02) 4655 0745 Fax: (02) 4655 6942 Email: jennih@camden.usyd.edu.au

Objectives • To identify the risk factors associated with development of inflammatory

airway disease (IAD) in young racing thoroughbreds. Studies will investigate the presence of pollutants and aero-allergens in racing stables and their association with development of IAD in a number of different stable management conditions. The role of viral and bacterial infections in IAD and their interplay with pollutants/aero-allergens will also be studied

Current Progress

The collection of tracheal wash (TW) and blood samples, and management and environmental data from 235 horses, on 3 occasions, 2 weeks apart, has been completed. Cytological and bacteriological analysis has been performed on all TW samples and serological analysis performed on blood samples. Sixty-five cases of IAD and 85 controls were identified and respirable and total dust samples and ammonia and carbon dioxide gases have been collected from these horses. Analysis of data is pending although preliminary results show that the prevalence of IAD in young thoroughbred racehorses that entered racetrack stables for 2 weeks is 36%, with inflammation persisting for 4 weeks in almost half these horses. Four preliminary studies also have been completed. The first established that the concentration of endotoxin in respirable dust samples collected from the breathing zone of horses stabled on straw and wood shavings agreed with previous studies and confirmed endotoxin’s significance as a possible risk for IAD in racehorses. In order to strengthen the validity of dust measurements, the second study determined repeatability and variability of endotoxin and glucan in respirable and total dust samples collected over 24 hours, in the breathing zones of racehorses housed in Sydney metropolitan racetrack stables. The third study showed that percentage of neutrophils in TW samples collected from horses after exercise was higher than percentages in TW before exercise, emphasizing the importance of exercise as a factor to consider when interpreting TW samples. In the fourth study, we established that TW samples reveal an inflammatory process distinct from that found using BAL samples suggesting inflammation could be restricted to particular regions of the airway and is not always a diffuse process.

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Project Title

An epidemiological study of 'tying up' in athletic horses

RIRDC Project No.:

US-83A

Start Date: 20/03/00 Finish Date: 30/09/03 Researcher: A/Prof. David Hodgson Organisation: The University of Sydney

University Veterinary Centre Department of Veterinary Clinical Sciences PMB 4, Narellan Delivery Centre NARELLAN NSW 2567

Phone: (02) 4655 0777 Fax: (02) 4655 6942 Objectives • 'Tying up' results in significant economic loss within the horse industry. An

improved understanding of the incidence, prevalence and risk factors for TU will translate into development of superior management strategies for this complex syndrome. This, in turn, will result in reduced wastage within the industry and have positive welfare implications

Current Progress

During 2001, a questionnaire was designed to determine the prevalence of Tying-Up (TU) in the Australian equine population. It was distributed to 1372 horse owners, who were a random sample of over 20,000 horse owners supplied by veterinarians across NSW. Data was received from 688 horse owners and included information on 4015 horses. Of these, 2144 horses were exercising and detailed analyses concentrated on this group of horses (as TU is considered an exercise induced disease). Prevalence of TU was determined in the general and exercising population, and also in different breed, age, sex and activity groups of the population. This information is currently being prepared for publication. The questionnaire also collected information on other common equine disorders such as colic, lameness, respiratory disease and weight loss, which is to be analysed similarly to the TU data and submitted for publication in mid 2002. Also in 2001, a case-control study investigating TU was established and is being conducted through 85 veterinary practices across Australia. Concurrently, over 1100 horses owned by questionnaire volunteers are involved in a cohort study. Prevalence data suggest that the case-control and cohort studies would need 12-18 months to collect the required number of cases and controls for analysis of other reported risk factors of TU, such as diet, exercise routine, previous TU or concurrent disease, fitness, management and temperament. These studies are due to be completed in early 2003 and should provide valuable information regarding the modifiable risk factors of this common, debilitating disease of horses in Australia.

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Project Title

Investigations of Equine Herpesvirus 1 cycle of infection in foals

RIRDC Project No.:

US-96A

Start Date: 30/06/02 Finish Date: 01/08/00 Researcher: A/Prof. Millar Whalley and (A/Prof D. N. Love) Organisation: Macquarie University Sydney Unviersity

SYDNEY NSW 2109 Phone: (02) 9850 8200 Fax: (02) 9850 8245 Email: mwhalley@rna.bio.mq.edu.au

Objectives • To provide an accurate indication of the epidemiology of equine herpesvirus

1 (EHV-2) infection in a group of very young foals on stud farms in Hunter Valley of NSW to add support to the concept of a cycle of silent EHV-1 infection.

• To provide evidence of response to vaccination with a commercially available killed EHV1/4 vaccine in young foals less than, and greater than, 5 months of age using type specific gG ELISA and virus neutralization assays.

• To provide evidence of response of mares to vaccination with a commercially available killed EHV1/4 vaccine in mares using type specific gG ELISA and virus neutralization assays.

• To show the amount of antibody passed on to foals in colostrum and how long this antibody level lasts in foals.

Current Progress

An initial study carried out during the breeding season of 1999 described serological evidence of infection in very young foals. We have now completed a more comprehensive study of 904 samples collected in 2000 from 239 mares and their foals over a four-week period during the breeding season on a major Hunter Valley stud farm. Analysis of nasal swabs identified 48 EHV-4 PCR-positive and 6 EHV-1 PCR-positive foals, indicating infection by the respective viruses. The youngest EHV-4 and EHV-1 positive foals were 11 and 22 days of age respectively. When combined with serological data from other studies the 2000 information provides evidence for a continuing cycle of infection of EHV-1 and EHV-4 in foals, despite the introduction of routine vaccination in 1997. The results combined with epidemiological data over 1999 to 2001 provide valuable information for management on large stud farms. At the same time the findings emphasize the necessity for improved vaccines and/or modified vaccine strategies. In another part of the research we are analyzing the relationship of maternal antibody to the age of foals that respond to vaccination with a new subunit vaccine.

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Project Title

Prospective Longitudinal Study of disease on Equine Stud Farms

RIRDC Project No.:

US-108A

Start Date: 14/08/01 Finish Date: 01/05/04 Researcher: Dr. James Gilkerson Organisation: The University of Sydney

Hunter Valley Equine Research Centre PO Box 25 Bunnan Road SCONE NSW 2337

Phone: (02) 6545 1607 Fax: (02) 6545 3444 Email: jgilkers@rna.bio.mq.edu.au

Objectives • Create an 'Industry Benchmark' for the diseases studied.

• Investigate the effects of disease in foals on their progression into performance horses

Current Progress

Sixteen Thoroughbred horse farms have enrolled in an active, prospective surveillance system which is designed to calculate the incidence, prevalence and cost of a range of equine diseases. This project has widespread support within the Thoroughbred breeding industry and aims to provide both breeders and researchers with accurate data as to the relative importance of common diseases of horses such as rattles (Rhodococcus equi pneumonia), strangles (Streptococcus equi ss equi infection), colic, developmental orthopaedic disease, musculoskeletal diseases and diseases of newborn foals such as septicaemia, isoerythrolysis and hypoxic ischaemic syndrome. Funds secured from RIRDC have been used to develop a database system that sources the data from the farm records directly and automatically compiles the data in a central database. To date, a minimum set of information has been identified and this information has been collected from most of the biggest farms in the study and is currently being analysed. Preliminary discussions with farms in Victoria and Queensland have been very positive and the plans to expand the study population base into these states are in place.

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4. Nutrition Research-Developing Better Ways to Feed Horses Project Title

Objective measurement of fodder quality across animal species

RIRDC Project No.:

DAV-187A

Start Date: 12/12/00 Finish Date: 09/09/02 Researcher: Mr. Peter Flinn Organisation: Department of Natural Resources & Environment (Vic)

Private Bag 105 HAMILTON VIC 3300

Phone: (03) 5573 0915 Fax: (03) 5571 1523 Email: flinnp@hammy.agvic.gov.au

Objectives • A set of "standard" fodder samples with measured in vivo digestibility,

intake and preference across beef cattle, lactating dairy cows, horses and sheep, to be used as a basis for a uniform objective procedure for the specification of fodder quality.

Current Progress

Twenty-one different hays, comprising cereals and legumes, were selected and purchased on the basis of chemical composition. Measurements of preference and feed intake rate have been completed on the hays for sheep, beef steers, horses and dairy cows. Digestibility and ad libitum intake measurements have also been completed on a smaller number of hays for all animal species except sheep. Near infrared (NIR) spectroscopy has been used to predict nutritive value on over 1000 hay samples used in the preference trial. There were clear differences in preference between hays within each animal species, but there was some overlap. There was more variation in preference across animal species for legumes than for cereals, and also more variation in nutritive value of the legume hays. Preliminary analysis suggests that dry matter digestibility correlates better with preference than other nutritive value estimates. Water-soluble carbohydrates appeared poorly correlated with preference for the cereal hays. Preference was strongly correlated with feed intake rate across animal species. Digestibility and intake measurements with sheep are still in progress. Laboratory analysis of the hays and detailed statistical analysis of the data also remains to be completed.

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Project Title

Glucose synthesis in equine hepatocytes

RIRDC Project No.:

ULA-14A

Start Date: 28/02/02 Finish Date: 30/12/02 Researcher: Dr. Theresa Frankel Organisation: La Trobe University

Department of Agricultural Sciences BUNDOORA VIC 3083

Phone: (03) 9479 2180 Fax: (03) 9471 0224 Email: T.Frankel@latrobe.edu.au

Objectives • Provide training in research for an Honours student.

• Modify the technique for isolation of ovine hepatocytes so it can be used on equine livers.

• Determine the in vitro effects of hormones and other metabolites on glucose synthesis in isolated hepatocytes.

• Determine the effects of diet on the ex vivo rate of glucose synthesis from propionic acid in isolated hepatocytes.

Current Progress

Elysia Campbell, a BSc (Animal Science) Honours student, enrolled in March. Preliminary studies to optimise the methodology using livers from horses killed for pet meat have been carried out. Equine liver morphology varies greatly: this makes it difficult to obtain a suitable sampling site. After examining a number of livers, we selected the left medial lobe to use for hepatocyte isolation. The caudate process of the right lateral lobe (similar to that used in sheep) has a distinct blood supply which would allow effective perfusion with collagenase. However, it is sometimes too small to be useful and is often damaged by the slaughter men during removal. We have developed a protocol that produces a good yield of viable cells even though it is over an hour before we can get the lobe from abattoir to laboratory. Initially the methodology we used produced hepatocytes of poor viability. We can now obtain good yields of viable cells by perfusing the lobe, at the abattoir, with an ice-cold solution containing EGTA. The remaining objectives will be carried out in he second half of the year after the major course work components of the BSc (Hons) year end in the middle of June.

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Project Title

Nutrient intake and growth of young horses

RIRDC Project No.:

UQ-72A

Start Date: 01/07/98 Finish Date: 30/06/01 Researcher: Dr. Neil McMeniman Organisation: The University of Queensland

School of Veterinary Science ST LUCIA QLD 4072

Phone: (07) 3365 1108 Fax: (07) 3365 1288 Email: n.mcmeniman@mailbox.uq.edu.au

Objectives • To determine whether weanling horses grazing lush spring pastures can

suffer a check in growth and whether this check is due to the fact that the high soluble carbohydrate containing diets contain insufficient fibre. The consequences in terms of subsequent growth and skeletal development to a check in growth will be determined.

• The project will also provide information on the effect of pasture maturity and yield on intake and growth of young horses.

• Information on which pasture species young horses prefer to consume will also be obtained.

Current Progress

A series of experiments was conducted to examine the relationships between pasture characteristics such as digestibility, yield, height and species on intake of dry matter by young horses. Summer (lucerne) and winter (ryegrass) pastures were planted and grazed. The characteristics of the pastures were varied by planting them at different rates to obtain different yields, grazing at different times to obtain pastures of differing maturity (digestibility) and slashing pastures to different heights before allowing them to regrow. Pasture intake by the horses was determined using the N-alkane marker technique For both summer and winter pastures there were positive relationships between intake and digestibility of diets. Pasture height and yield were also positively related but yield did not influence intake while increasing pasture height depressed intake. It was also found that as the amount of leaf in the diets increased so did the digestibility of the diets and, conversely, increasing stem in the diet depressed digestibility. Therefore, the results of the study show that, as expected, as digestibility of the diets increased so did intake but neither of these measures was significantly affected by altering the pasture characteristics. It has been suggested that horses prefer to have a proportion of low digestibility fibre in their diets, especially when grazing lush young pastures. However, in an experiment where horses grazing young ryegrass pastures were given access to oat straw, no straw was eaten. The results of the experiments require further statistical analyses.

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5. Lameness and Limb Injury-Developing More Effective Methods for Prevention, Diagnosis and Treatment Project Title

Pasture fructan concentration as a cause of equine laminitis

RIRDC Project No.:

UQ-100A

Start Date: 01/12/01 Finish Date: 30/11/04 Researcher: Dr. Christopher Pollitt Organisation: The University of Queensland

School of Veterinary Science ST LUCIA QLD 4072

Phone: (07) 3365 2063 Fax: (07) 3365 1899 Email: c.pollitt@mailbox.uq.edu.au

Objectives

• The cause of grass founder will be understood and a strategy for diagnosis, prevention and treatment will be available

• A strategy for pasture and grazing management will be available so that horses and ponies do not consume sufficient fructan to develop laminitis

Current Progress

Alimentary overload with fructan, in the form of commercial oligofructose (OF) causes laminitis. Six horses dosed with 7.5, 10 & 12.5 g/kg all developed laminitis in at least one foot. There was a significant correlation between dose and laminitis severity and none developed colic. All the horses developed profuse, acid diarrhoea and fever. Blood D-lactate, of bacterial origin, peaked at 24 hours at a concentration far in excess of that reported in similar studies using wheat starch. Since all horses developed laminitis, the results establish that a storage carbohydrate, other than starch, can induce the disease. OF is a principal nonstructural carbohydrate of pasture grasses, suggesting it is grass OF that causes laminitis and not other substance(s), such as dietary amines. Alimentary overload with fructan is an efficient and more humane experimental model for the induction of acute laminitis. A technique for cannulation of the horse’s caecum has been developed and, after dosing with OF changes, in caecal microbes will be monitored, using total counts and fluorescent in situ hybridisation (FISH). A panel of FISH probes has been successfully tested on faecal smears showing that hindgut streptococci are the dominant microbes after OF dosing.

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Project Title

An epidemiological study of risk factors for shin soreness in Thoroughbred racehorses

RIRDC Project No.:

US-84A

Start Date: 02/01/00 Finish Date: 31/07/03 Researcher: A/Prof. David Evans Organisation: The University of Sydney

Faculty of Veterinary Science University of Sydney B19 SYDNEY NSW 2006

Phone: (02) 9351 2474 Fax: (02) 9351 3957 Email: davide@vetsci.usyd.edu.au

Objectives • The objective of this project is to undertake an epidemiological study of the

risk factors for shin soreness in Thoroughbred horses. A better understanding of the risk factors will facilitate design of superior training and managment strategies for Thoroughbred horses, and a reduction in wastage due to shin soreness

Current Progress

The study population consisted of horses foaled in 1998 (Cohort A) and 1999 (Cohort B), trained by participating trainers. Eighteen trainers, at 3 metropolitan and 2 provincial racetracks, were enrolled in the study. The trainers where visited fortnightly to collect training and musculoskeletal injury (MSI) data. Data analysis of cohort A's two-year-old racing season involved descriptive statistics for the study population, training data and injury data, and a Chi squared analysis to determine if the proportion of horses injured varied between racetracks and trainers. There were 422 horses in Cohort A, of which 206 were male and 216 were female. The prevalence of MSI was 45% with values for individual trainers ranging from 11% to 83%. The prevalence of MSI at each of the 5 racetracks ranged from 28% to 52%. Chi-square analysis found a significant difference in prevalence of MSI between individual trainers (p

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7. Reducing Reproductive Failure in Mares and Stallions and Establishing more Effective Treatments for Diseases of Foals Project Title

Further development of vaccines against rhodococcus equi infection in foals

RIRDC Project No.:

IMV-4A

Start Date: 01/01/02 Finish Date: 01/01/04 Researcher: A/Prof. Mary Barton Organisation: Institute of Medical & Veterinary Science

School of Pharmaceutical, Molecular and Biomedical Sciences GPO Box 2471 ADELAIDE SA 5001

Phone: (08) 8302 2933 Fax: (08) 8302 2389 Email: mary.barton@unisa.edu.au

Objectives • Development of an improved animal model of R. equi infection for the

testing of candidate vaccines. • Development of a GroEL/VapA epitope chimeric (combination)

protein/DNA vaccine • Testing of vaccines against R. equi based upon the VapA and GroEL

proteins in a non-equine model of R. equi infection and demonstration of an efficacious vaccine that protects against R. equi induced pneumonia.

Current Progress

The ELISA test developed in the earlier grants was further validated using additional sera. This sera was obtained from the United States and Australia. One set of sera was taken at 7 and 14 days from foals artificially infected with R. equi. The ELISA did not detect anti VapA antibodies at 7 days post-infection, but very strong reactions could be detected at 14 days post infection. This suggests that the ELISA is able to detect antibodies to VapA between 8 and 14 days post infection. Sera taken from adult horses that had been immunised against VapA were tested in an ELISA against a complete VapA peptide bank. The results suggested that adult horses often recognise different epitopes in addition to the epitope identified in previous grants. The significance of this observation is yet to be determined. GroEL/VapA combination vaccines have been developed and tested in a murine model. The results suggested an immune response with a Th1 bias. The Th1 cell mediated response is predicted to be protective against intracellular pathogens such as R. equi. The development of an improved non-equine model of R. equi infection will begin immediately a new animal facility at IMVS is commissioned.

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Project Title

Evaluating equine immune responses to new EHV-1 vaccine candidates

RIRDC Project No.:

UMA-17A

Start Date: 14/08/01 Finish Date: 30/06/03 Researcher: A/Prof. Millar Whalley Organisation: Macquarie University

Department of Biological Sciences SYDNEY NSW 2109

Phone: (02) 9850 8200 Fax: (02) 9850 8245 Email: mwhalley@rna.bio.mq.edu.au

Objectives • Improvement of reproductive efficiency and respiratory health in horse

populations through reduction of incidence of herpesvirus abortion and respiratory infection, at reduced costs, by:

• Developing an experimental challenge protocol for assessment of equine herpesvirus 1 (EHV-1) vaccines.

• Evaluation of immune responses and ability of new vaccines to prevent respiratory or systemic infection.

• Reaching new stage in development of Australian made vaccine for EHV-1.

Current Progress

An EHV-1 infection challenge model has been established at Murdoch University, Perth. Five foals aged between two and four months of age were inoculated with EHV-1 and monitored or sampled over the subsequent four weeks. Clinical signs including a serous to sero-mucinous nasal discharge and swelling of the submandibular lymph nodes, as well as an elevation in temperature were observed in all five foals from between two and four days post-challenge. A reverse neutrophil:lymphocyte ratio was observed in three foals between day five and day seven. An elevation in anti-EHV-1 antibody was observed from day four and EHV-1 DNA was detected from nasal swabs from day three in all foals and in peripheral blood from day eight in four foals. All foals fully recovered by the conclusion of the sampling period. In the other arm of the project, the data indicate that although there may be cell-mediated responses to early inoculation with DNA or protein, using antibody as a measure of response the preferred age for vaccination should not be earlier than around four months. Together these experiments now lay the groundwork for experimental challenge of foals after vaccination.

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Project Title

Analysis of horse breeding efficiency in Australia

RIRDC Project No.:

UMO-26A

Start Date: 20/07/99 Finish Date: 01/06/03 Researcher: Dr. Angus McKinnon Organisation: Monash University

PO Box 905B Goulburn Valley Highway CONGUPNA VIC 3630

Phone: (03) 5829 9566 Fax: (03) 5829 9307 Email: aom@mail.sheppnews.com.au

Objectives • Analysis of breeding record via the Stud Books. This is only expected to

provide an overview of industry practices. For a variety of reasons, records submitted to the Stud Book (both racing codes) are only a superficial view of breeding practices, however they do represent the true and relevant fertility's of the different breeds and even different stallions on the same breeding farms.

• Analysis of individual mare records from selected breeding farms. • This is an ambitious attempt to collate data from a wide variety of sources. • It is estimated that 30,000 individual mare records of each breed from a

variety of studs that have been chosen to represent three levels of management will be used to compare factors such as fertility per cycle, effect of fuid pre and post service, effect of scanning or not, rate and time period of early embrionic death, etc. Provisional data will be obtained from our own breeding records, (we have 3000 already analysed and 4000 to put on the database

Current Progress

The horse breeding efficiency database contains approximately half of the targeted number of records. The progress is within the expected timeframes (adjusted). Dr. McKinnon will take the database to Dr. Dargatz of the USDA in early July and a preliminary set of statistics created. These will be used to model the final statistical analysis in approximately one year’s time. Preliminary database statistics have been published on our web site at http://www.gvequine.com.au/

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9. Other Project Title

2002 Bain-Fallon Conference (Gold Coast)

RIRDC Project No.:

EVA-1A

Start Date: 28/09/01 Finish Date: 30/06/02 Researcher: Dr. James Gilkerson Organisation: Australian Equine Veterinary Association

Hunter Valley Equine Research Centre PO Box 25 Bunnan Road SCONE NSW 2337

Phone: (02) 6545 1607 Fax: (02) 6545 3444 Email: jgilkers@rna.bio.mq.edu.au

Objectives

• To support the Bain-Fallon Conference (Gold Coast)

Current Progress

The Australian Equine Veterinary Association will hold its annual conference on the Gold Coast between the 22nd and 26th of July 2002. On Wednesday 24th of July the AEVA will host the first RIRDC Research colloquium which will highlight some of the innovative equine research that Australian researchers are conducting with RIRDC support. The programme for the research colloquium covers research into several infectious diseases, musculoskeletal and structural respiratory disease, the pharmacology of novel non-steroidal anti-inflammatory drugs, as well as some preliminary results from a equine surveillance project. Australian researchers are recognised in the forefront of their respective fields, yet these world class researchers have not previously had a forum to present their results to the equine veterinary profession. RIRDC funds have enabled the AEVA to secure this wide range of Australian speakers and the Bain Fallon conference provides these researchers a unique opportunity to present their work to Australian equine veterinary practitioners at the premier Australian equine veterinary conference.

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Project Title

Scholarship - Nerida McGilchrist

RIRDC Project No.:

UNE-78A

Start Date: 31/12/02 Finish Date: 01/12/00 Researcher: Ms. Nerida McGilchrist Organisation: University of New England

ARMIDALE NSW 2351 Phone: (02) 6773 5135 Fax: (02) 62773 3275 Email: nmcgilchrist@metz.une.edu.au

Current Progress

My PhD for which RIRDC has provided scholarship money, has focused primarily on the digestion of starch in the horse’s small intestine, the limitations to starch digestion in the small intestine of the horse and methods that may be used to maximise small intestinal starch digestion. The glycaemic response and an enzyme based in vitro assay have been developed as methods for estimating the digestion of starch in the horse’s small intestine. RIRDC provided funding to conduct a thoroughbred industry survey that allowed us to determine which grains were being fed in industry; the quantities of grains being fed; and the processing methods used by trainers prior to feeding the grains. 72 thoroughbred trainers from Grafton to Warwick Farm in NSW were surveyed on a face-to-face basis. 80.6% of trainers fed oats, 73.6% of trainers fed corn and 73.6% of trainers fed a commercial premixed diet. Barley was fed by just 33.3% of trainers. Oats and premixed diets were fed in the greatest quantities averaging, when fed, 3.58 kg and 2.48 kg/horse/day respectively. Physical cracking was the most commonly used processing method for grains fed to thoroughbreds with more than 40% of grains fed, cracked prior to feeding. Just 20% of grains fed were either micronised, steam flaked or extruded prior to feeding.

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Project Title

Scholarship - Sundrela Kamhieh

RIRDC Project No.:

US-113A

Start Date: 31/12/04 Finish Date: 01/01/02 Researcher: Ms. Sundrela Kamhieh Organisation: The University of Sydney

SYDNEY NSW 2006 Email: skamhieh@yahoo.com

Current Progress

In Europe, Borna disease virus (BDV), a unique RNA virus (Bornaviridae), has been identified to cause neurological syndromes in various animal species. In horses and sheep, this can further develop into Borna Disease, a fatal neurological disease characterised by meningoencephalomyelitis. The two foci of this study are whether BDV infection is present in Australia and whether there are changes in infected animals associated with disease. A comprehensive sero- and molecular-epidemiological study is being conducted on horses, cats and humans. Serum and EDTA samples have been collected from over 200 horses and will continue throughout 2002 until 2004, starting in NSW and eventually nationwide. For the seroepidemiological aspect of the project, a “triplet” assay will be utilised based on the detection of circulating immune complexes (CICs), free antibodies and antigens. Furthermore, a novel peptide ELISA has been developed based on eight epitopes (e) of the BDV p23 phosphoprotein. RT-PCR, virus isolation and immunocytochemical procedures will also be employed. In preliminary studies, CICs were detected in four of 200 horses tested, whereas with the peptide ELISA, seven of 158 horses were seroreactive. Hyperbilirubinaemia was observed in three of these horses. Viral RNA has not been detected in 171 horses by RT-PCR.

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