RIRDC Completed Projects in 2000-2001 & Research in Progress as at June 2001

BACK TO INDEX

To Horses  Completed Projects




3.5 HORSES  RESEARCH IN PROGRESS
PROJECT No	PROJECT TITLE	RESEARCHER	PHONE	ORGANISATION
1. Information Technology for the Horse Industry
US-102A	Racecourse Managers Research Planning Workshop	Ms Shirley Ray	(02) 9352 6932	The University of Sydney
US-103A	Production of a manual of equine exotic disease for the horse owner	Dr Jennifer Hodgson	(02) 4655 0745	The University of Sydney
US-95A	Communication and Information Programs for the Horse Industry	Ms Shirley Ray	(02) 9352 6932	The University of Sydney
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
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
UMU-25A	Role of latent equine herpesvirus infections in respiratory disease	A/Prof Graham Wilcox	(08) 9360 2448	Murdoch University
US-82A	A Longitudinal Cohort Study of Inflammatory Airway Disease in Racing Thoroughbreds	Dr Jennifer Hodgson	(02) 4655 0745	The University of Sydney
US-96A	Investigations of Equine Herpesvirus 1 cycle of infection in foals	A/Prof Daria Love	(02) 9351 2454	The University of Sydney
4. Nutrition Research-Development Better Ways to Feed Horses
UQ-72A	Nutritent intake and growth of young horses	Dr Neil McMeniman	(07) 3365 1108	The University of Queensland
5. Lameness and Limb Injury-Developing More Effective Methods for Prevention, Diagnosis and Treatment
UF-7A	To develop and implement a pilot project to determine the feasibility of monitoring injury to horse riders and handlers in New South Wales and South Australia	Dr Raymond Cripps	(08) 8374 0970	Flinders University of South Australia
UMU-24A	Investigation into radiographic changes in the carpus (C3) in racehorses	Dr Catherine Steel	(08) 9360 2356	Murdoch University
UQ-71A	Novel anti-inflammatory drugs to treat inflammatory diseases in horses	Dr Stephen Taylor	(07) 3365 3124	The University of Queensland
UQ-75A	The pathogenesis and prevention of equine laminitis	Dr Michael Pass Dr Christopher Pollitt	(07) 3365 3127 (07) 3365 2063	The University of Queensland
US-83A	An epidemiological study of 'tying up' in athletic horses	A/Prof David Hodgson	(02) 4655 2000	The University of Sydney
US-84A	An epidemiological study of risk factors for shin soreness in Thoroughbred racehorses	Dr David Evans	(02) 9351 2474	The University of Sydney
7. Reducing Reproductive Failure in Mares and Stallions and Establishing More Effective Treatments for Diseases of Foals
UMO-26A	Analysis of horse breeding efficiency in Australia	Dr Angus McKinnon	(03) 5829 9566	Goulburn Valley Equine Hospital

1. Information Technology for the Horse Industry
 

Project Title	Racecourse Managers Research Planning Workshop
RIRDC Project No.:	US-102A
Start Date:	01/02/01
Finish Date:	07/06/01
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	· Investigate the process for development of standards for racetracks. · Define a procedure for uniform racecourse data collection and analysis.
Current Progress	The Workshop was the outcome of a short forum on research and development priorities for racecourse management, held at the 5th Racecourse Managers’ Conference in Melbourne in June, 2000. Seventeen people were invited to attend the workshop, including four involved primarily 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.  The Workshop produced outlines of two similar, possible R & D projects, both connected with collection and collation of data that provides objective measurement of track shape, surface, maintenance and use, and the relationship of that data to horse injury, durability and performance. The projects could be run simultaneously, or as Phases 1 & 2; one concentrating on building a data base of current information (local and overseas) on "best practice" in track shape (layout and topography), surface (soil and turf profile), maintenance and use; the other concentrating on developing uniform measurement standards for track surface characteristics (shape, surface, and condition) and correlating these with horse injury and performance records.  Involvement of racing industry stakeholders (managers, engineers, turf experts, veterinary specialists, etc) in these projects was seen as important for pooling of knowledge and capabilities, and joint "ownership" of the R & D work and results. This would also be more conducive to racing industry financial and moral support. A team approach to the conduct of the projects was suggested under the guidance of an experienced researcher.


 

Project Title	Production of a "Manual of Equine Exotic Disease for the Horse Owner".
RIRDC Project No.:	US-103A
Start Date:	1/04/2001
Finish Date:	31/10/2001
Researcher:	Dr JL Hodgson
Organisation:	University of Sydney Faculty of Veterinary Science University Veterinary Centre Camden PMB 4, Narellan Delivery Centre Narellan, NSW, 2567
Phone:	02 4655 0745
Fax:	02 4655 1212
Email:	jennih@camden.usyd.edu.au
Objectives	· The objective of this project is to produce a Manual of Equine Exotic Diseases that would be easily accessed and comprehended by all interest groups in the equine industry. The outcome would be a valuable resource for horse owners as well as an important tool to help avoid the introduction of these potentially catastrophic diseases
Current Progress	The timeliness of this manual, with increased awareness of the importance of exotic diseases to a range of rural industries is important. The literature search for this manual has now been completed and the manual is on track to be completed by the designated date.


 

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: · 1. Ongoing Development of a Database of Equine Organisation (locally and internationally). To communicate with key industry groups. · 2. 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. · 3. 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 in excess 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 17,300 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.

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:	g.browning@vet.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	The optimal media for use in air sampling has been determined and probes to identify and distinguish avirulent and virulent Rhodococcus equi have been produced. Optimal conditions have been determined for blotting R. equi colonies and for hybridising blotted DNA to each of probes have been determined. Six studs from three distinct geographic regions have been sampled at monthly intervals throughout the 2000-2001 foaling season. Air samples have been taken from foaling areas and data on soil type and moisture, management and weather conditions have been compiled. In addition the use of breath sampling foals to detect infection has been assessed. Alternative selective media have also been assessed under environmental conditions and the best agars for sampling foals and for sampling air in paddocks, respectively, determined. Preliminary results have shown that on specific studs there was a dramatic increase in the proportion of virulent R. equi in October on specific studs.


 

Project Title	Improved vaccine strategies for management of equine herpesvirus diseases
RIRDC Project No.:	UMA-15A
Start Date:	01/07/98
Finish Date:	30/06/01
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. · Improved preventative strategies against infectious dieases of the horse, and lower costs. · Possible establishment of generic vaccine technology applicable to different diseases affecting horses.
Current Progress	Studies have been conducted to evaluate the vaccine potential of a formulated protein subunit vaccine. All horses tested had a specific immune response to a single inoculation of the vaccine, as seen by ELISA antibodies to the glycoprotein antigen (gD). The responses to the low dose inoculation were equivalent to those in the medium and higher doses. A second inoculation marginally boosted the ELISA antibody. The rise in gD antibody was accompanied by a rise in EHV-1 neutralising antibody. The results provide convincing evidence for the vaccine potential of this formulation and all results so far confirm the safety of the formulation. From the antibody and clinical surveillance, to date, the researchers have not detected any new EHV-1 infection or disease in the groups of horses that have received either the DNA or the formulated subunit vaccines.


 
 
 

Project Title	Role of latent equine herpesvirus infections in respiratory disease
RIRDC Project No.:	UMU-25A
Start Date:	01/07/00
Finish Date:	20/06/01
Researcher:	A/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	· To provide evidence that some strains of EHV2 are causes of respiratory disease, perhaps acting as stressors activating other latent equine herpesviruses, by 2001. This is a pilot project to assess the importance of EHV2 as a potential pathogen preliminary 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
Current Progress	Epidemiological and experimental studies were undertaken to evaluate the role of equine herpesviruses (EHV), particularly EHV2, in respiratory disease in young horses: 1. Epidemiologic studies. Nasal swab and peripheral blood samples were obtained from 73 Thoroughbred and 40 Standardbred foals from 10 studs at weaning, immediately prior to sale or immediately after sale. Respiratory disease was associated with detection of EHV2 in samples from some of these horses.  2. Experimental studies. Mixed breed yearling horses (14) were experimentally infected with EHV2, isolated from horses with respiratory disease, or served as uninfected controls. Apparent recrudescence of latent EHV4 and EHV2 was associated with clinical signs of mild respiratory disease in control horses. Experimental infection with EHV2 was difficult to achieve, requiring large doses of infectious virus in sedated horses (unsedated horses appeared 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. EHV2 induced disease was self-limiting, with complete recovery within 10 – 14 days.


 
 

Project Title	A Longitudinal and Case Control Study of Inflammatory Airway Disease in Young Racing Thoroughbreds
RIRDC Project No.:	US-82A
Start Date:	26/07/99
Finish Date:	31/07/02
Researcher:	Dr. Jennifer Hodgson
Organisation:	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 1212
Email:	Jennih@camden.usyd.edu.au
Objectives	· To identify non-infectious, management and environmental risk factors associated with the development of Inflammatory Airway Disease (IAD) in 2-3 year old racing thoroughbreds. The role of viral and bacterial infections in IAD and their interplay with these factors will be concurrently studied. · To monitor the status of IAD in 2-3 year old racehorses entering racetrack stables during 4 weeks of training to determine the incidence of IAD.
Current Progress	The collection of tracheal wash (TW) and blood samples, managerial data and environmental data has progressed over the last 13 months. TW samples (three collection times 2 weeks apart) from 170 horses have been obtained. Collection will continue throughout 2001 until samples and data from 250 horses have been obtained. Thirty-nine cases of IAD and 84 well-defined controls from these 150 horses have so far been identified and respirable and total dust samples and ammonia and carbon dioxide gases have been collected from these horses. Samples from at least 50 cases and 100 controls will be obtained. A pilot study also has been performed in which the concentration of endotoxin in respirable dust samples collected from the breathing zone of horses stabled on 2 types of bedding over time has been calculated. In addition, in an associated study, the difference between tracheal wash cytological samples collected from horses before and after exercise on a high-speed treadmill and the relationship between interpretation of IAD in TW cytology and BAL cytology after exercise has been established. Finally, validation of the Allergen Particle Immuno-staining assay for horses to determine if allergens are involved in IAD is now underway. Results of preliminary experiments have shown promise.


 
 

Project Title	Investigations of Equine Herpesvirus 1 cycle of infection in foals
RIRDC Project No.:	US-96A
Start Date:	01/08/00
Finish Date:	30/06/02
Researcher:	A/Prof. Daria Love
Organisation:	The University of Sydney Faculty of Veterinary Science Building B14 SYDNEY NSW 2006
Phone:	(02) 9351 2454
Fax:	(02) 9351 7348
Email:	dlove@angis.usyd.edu.au
Objectives	· To provide an accurate indication of the epidemiology of equine herpesvirus 1 (EHV-1) 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	Over a three week period during the stud season, nasal swab samples were taken from foals and mares as they entered the crush for routine reproductive procedures. In total, 960 samples were taken during October/November 2000. Samples were subjected to a PCR to detect EHV-1 and EHV-4. Fifty foals ranging from 11 days to 90 days of age were excreting EHV-4 and two foals were positive on more than one occasion. Two mares were infected with EHV-4. EHV-1 was detected in six foals ranging in age from 22 says to 58 days and from one mare. This is the first report in the world showing infection of foals of this age with EHV-1 and EHV-4 and supports the serological evidence of a silent cycle of EHV-1 (and EHV-4) infection. It has profound implications for the industry and for management procedures such as vaccination on stud farms. 159 mares and 101 foals were vaccinated with a commercial EHV-1/4 vaccine in 2001 and serological responses measured by ELISA. 13.8% of mares and 46.6% of foals responded to vaccination using one ELISA assay, while 28.9% of mares and 42.6% of foals responded to vaccination using a different ELISA assay. Between 16.4% and 17.6% of mares were considered carriers of EHV-1 using these assays. Eight of the 101 foals (7.9%) became infected with EHV-1 or EHV-4 during the study. Four of these foals had been categorised as responders to vaccination.

4. Nutrition Research-Developing Better Ways to Feed Horses
 

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	The majority of the research that was conducted in the project ‘Nutrient intake and growth of young horses’ dealt with discovering the effect of pasture maturity and yield on the intake of young horses. Several different treatments were used over the 3 years of research including slashing, controlled grazing, varying stocking rate and varying sowing rate. Horses showed an expected preference for young lush, over older mature grass. It was also found that their intake was reduced when ample pasture was on offer. When pasture height and yield declined below a certain level intake was again restricted even though the quality of pasture was highest. When pasture was young and lush, young horses showed no specific selection for leaf over stem, but when pasture maturity increased and stem digestibility decreased selection for leaf approached 100 percent. Although trials were not set up to specifically ascertain what species horses preferred, certain preferences were noted. For temperate species horses selected rye over oats, with very little selection towards white or subterranean clover. For forage legumes they showed preferences for Lucerne over white clover. For topical grasses Callide Rhodes grass was preferred over Kikuyu, and Pitted Blue grass and African Star grass were only heavily grazed when other species had been grazed out. The intake of young horses on lush rye grass was measured to determine whether intake was reduced due to high levels of soluble carbohydrates and low fiber content. It was found that intakes were not depressed and that when horses were offered a high fibrous supplement of oaten hay none of it was selected even though the pasture being consumed was very low in fiber. More research needs to be conducted in this area with perhaps more effort being put into looking at how soluble carbohydrates may effect selection with regards to palatability and possible mild acidosis.

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

Project Title	To develop and implement a pilot project to determine the feasibility of monitoring injury to horse riders and handlers in New South Wales and South Australia
RIRDC Project No.:	UF-7A
Start Date:	16/02/01
Finish Date:	01/03/02
Researcher:	Dr. Raymond Cripps
Organisation:	Flinders University of South Australia Research Centre for Injury Studies Mark Oliphant Building, Laffer Drive BEDFORD PARK SA 5042
Phone:	(08) 8374 0970
Fax:	(08) 8374 0702
Email:	ray.cripps@nisu.flinders.edu.au
Objectives	§ The research program will determine the feasibility of establishing a surveillance program to monitor falls at specific equestrian events, ie one-day and three-day events (ODEs and 3Des). If this pilot is successful, this proposed research will: · Broaden the scope of equestrian injury monitoring in Australia · Investigate the causes of injury to riders at Equestrian Federation of Australia (EFA) and Federation Equestre Internationale (FEI) events in  · South Australia and New South Wales · Will inform the development of further research to identify factors that may increase the risk of injury to riders, and develop and evaluate  · Interventions to reduce injuries to riders
Current Progress	The project which has just completed its third month has achieved the following: 1) Informed key personnel in South Australia and New South Wales of procedures required for monitoring of falls at ODEs and 3DEs, ie. recording and reporting. 2) Developed and produced a questionnaire to send to equestrians who fall. 3) Development of a database data entry/reporting system for fall reports, stewards reports, and returned eventing fall questionnaires is in progress. 3) Monitoring of eventing falls during ODEs and 3DEs in South Australia and New South Wales has begun. A summary of fall monitoring during events in South Australia and New South Wales is presented below: SOUTH AUSTRALIA There are 12 official EFA events scheduled for 2001 in South Australia, of which 3 have so far been held. The names of fallen riders and particulars of the falls which occurred in all three events have been received. There have been a total of 14 falls, by thirteen different riders, including one which was a ‘technical’ fall only ie the rider dismounted voluntarily with no injury to either horse or rider. The average number of falls per jumping effort is 1/498.4, including the ‘technical’ fall.  All data regarding the falls has been received within a fortnight of the event being held. Questionnaires have been sent to all riders concerned. So far there have been three responses to these questionnaires. NEW SOUTH WALES 34 official EFA events are scheduled to be held in NSW during 2001, of which 7 have taken place. Falls data for six of these events have been received. There has been a total of 35 falls, by 33 riders in these six events. It is not possible to give an average of falls/jumping effort for New South Wales, due to the different data received from South Australian and New South Welsh sources. The data was initially reaching us about a month after the event had taken place, but the process has now been streamlined and is reaching us in about a fortnight.  Due to the number of interstate riders competing in New South Welsh events, it is sometimes difficult to obtain address details for riders who have fallen, involving contact with the Victorian branch of the EFA, as well as the NSW branch.  So far 31 questionnaires have been sent to riders for whom address details have been found, and 2 have been returned.


 

Project Title	Investigation into radiographic changes in the carpus (C3) in racehorses
RIRDC Project No.:	UMU-24A
Start Date:	20-07-99
Finish Date:	30-11-01
Researcher:	Dr Catherine Steel
Organisation:	Murdoch University Veterinary Hospital Murdoch Drive Murdoch WA 6150
Phone:	(08)9360 2356
Fax:	(08)9310 7495
Email:	Csteel@central.murdoch.edu.au OR colbourn@numbat.murdoch.edu.au
Objectives	§ Describe radiographic changes in the third carpal bone (C3) in a large group of racehorses during their 1st year of training using a system of interpretation of radiographs that can be readily applied by veterinarians in practice. § Correlate radiographic findings with clinical findings in order to determine the clinical significance of various radiographic changes in C3, and to determine radiographic changes that may predict the onset of carpal lameness due to C3 sclerosis, chip fracture, slab fracture and osteoarthritis of the carpus, which often result in wastage due to lost training time or retirement. § To determine the influence of training and rest on the progression and/or resolution of radiographic changes so that recommendations can be made to trainers and owners regarding the management of horses with clinically significant C3 sclerosis and the prevention of carpal lameness.
Current Progress	108 Standardbred horses are examined for lameness and carpal radiographs are obtained every 3 months from the onset of training and during the 1st 12-18 months of training. In addition, 7 age-matched, untrained Standardbreds have been examined and radiographed every 3 months over the same period. To date, 32 horses (32/108=30%) have been lame in 1 or both forelimbs when examined. Of these, the lameness has been localised to the intercarpal joint using intra-articular anaesthesia in 21 horses (21/30=70%). In these horses, radiographic changes have been confined to C3 and have ranged from mild to moderate/severe sclerosis +/- lytic defects in the radial facet of C3. In non-lame horses, sclerosis has remained mild. Preliminary results indicate that horses with intercarpal joint lameness have an increased average grade of sclerosis compared to non-lame horses, and a greater % area of the radial fossa of C3 affected. Scintigraphic examination of a selection of horses from the lame and non-lame groups is underway. Carpal radiographs and CT scans have been obtained from a separate group of 18 horses. Diagnostic imaging findings from all horses are currently being recorded and correlated with clinical findings and exercise history.


 

Project Title	Novel anti-inflammatory drugs to treat inflammatory diseases in horses
RIRDC Project No.:	UQ-71A
Start Date:	01/09/98
Finish Date:	01/09/01
Researcher:	Dr. Stephen Taylor
Organisation:	The University of Queensland Dept of Physiology and Pharmacology BRISBANE QLD 4072
Phone:	(07) 3365 3124
Fax:	(07) 3365 1766
Email:	s.taylor@mailbox.uq.oz.au
Objectives	· To test novel classes of anti-inflammatory drugs that will reduce the impact of inflammatory diseases of the lung, eye and joint on the normal structure of affected tissues in horses. By reducing fibrosis, oedema, cellular hyperplasia and changes in the phenotype of resident cells, the long term impact of inflammatory diseases, like pneumonia, arthritis and uveitis, on performance and well being will be reduced.
Current Progress	Part 1 Model of equine colic A model of intestinal ischaemia/reperfusion injury was developed in the rat and closely mimicked the histological damage seen in the strangulated equine bowel. In this rat model of ischaemia/reperfusion a number of drugs were shown to offer significant protection. The C5a antagonist (1mg/kg I.V and 10mg/kg P.O.) completely protected the intestinal mucosa from damage induced by ischaemia/reperfusion. Pirfenidone and the phospholipase A2 inhibitor (KHO64, 5mg/kg I.V.) also gave protection to the intestine, but to a slightly lesser degree than the C5a antagonist. All drugs protected against intestinal oedema and lessened the impact of the intestinal pathology on neutrophil activation and remote organ damage as seen by normal plasma levels of tumour necrosis factor alpha (TNF?), aspartate transaminase (AST) and haptoglobin (a liver stress protein). In clinical cases of reperfusion injury, damage to remote organs, like liver, lung and heart, are often life-threatening. In some preliminary work being done with flunixin in the model this drug worsens pathology. There is some evidence that this correlates with clinical observations.  Part 2 Renal ischaemia model This rat model has now been developed and characterised and the C5a antagonist and KHO64 have been tested. Both drugs protected the kidney (histology, creatinine clearance and urinary protein) and also lessened the impact of the pathology on the whole animal - as seen by normal levels of plasma enzymes.


 

Project Title	The pathogenesis and prevention of equine laminitis
RIRDC Project No.:	UQ-75A
Start Date:	01/07/98
Finish Date:	30/06/02
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	· To determine the role and control the activity of matrix metalloproteinases in the pathogenesis of laminitis so that a product can be developed which will prevent and treat the disease. · To determine the role of changes in the pattern of glucose metabolism in the pathogenesis of laminitis as a basis for predicting and preventing laminitis.
Current Progress	The pathological mechanism that causes the pedal bone to separate from the inner hoof wall is now better understood. The genes controlling production of matrix metalloproteinases (MMP-2 & MMP-9), enzymes that normally control growth and remodelling of the continually growing hoof wall, are upregulated by the time laminitis first appears. The target of this increased MMP activity in laminitis is the basement membrane, a thin sheet of connective tissue that binds the hoof to the connective tissue of the pedal bone. The basement membrane is anchored to hoof lamellar cells by fine filaments at sites called hemidesmosomes. We have discovered that hemidesmosomes and anchoring filaments disappear early in natural laminitis and may be the earliest event in the process. Loss and separation of the lamellar basement membrane allows the hoof and pedal bone to come apart and is caused by uncontrolled MMP activation. However, we have discovered a second process (not involving MMP activation) that does the same thing; failure of lamellar glucose metabolism. This may explain why horses with glucose metabolism problems (Cushing’s Syndrome and Obesity) develop a slowly progressive chronic laminitis. Using our in vitro laminitis model we have shown that a toxin produced by hindgut Streptococcal bacteria activates hoof lamellar MMP thus mimicking the natural lesion of laminitis. We have confirmed that a sugar produced by grass (fructan) is a potent cause of laminitis. Thus when horses consume grass rich in fructan the microflora of the hindgut become unbalanced and a population explosion of anaerobic Streps occurs. The toxin they produce escapes into the circulation and activates the hoof MMP enzymes to cause laminitis. The testing of several preventive strategies, based on these discoveries, (eg MMP enzyme inhibition, Strep exotoxin neutralisation, cell glucose uptake studies and foot circulation manipulatiion) is currently underway.


 

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 2000
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	Tying-Up is a debilitating condition renowned for its continual presence in athletic horses despite regular attempts at prevention and treatment. Affected animals often have repeated bouts of Tying-Up regardless of many remedies used to manage the condition. The result is the potential for significant suffering of these horses and considerable wastage to equine industries.  In view of the complicated, multifactorial nature of Tying-Up in horses it is not likely that the causes(s) can be identified by relying solely on laboratory based research involving a relatively small number of affected individuals. Multifactorial diseases require an epidemiological (population-based) approach if the risk factors are to be successfully identified and modified. In this project we hope to address many of the unknowns of the epidemiology of Tying-Up in Australian horses. The study is being conducted nationwide through horse owners and veterinarians involved in varied equine activities. In response to some preliminary work with equine veterinarians in 2000, we plan to include a retrospective analysis of equine muscle enzyme activities in our investigation. This should help establish more reliable criteria for diagnosis and also aid the interpretation of information from the case-control study. A nationwide questionnaire distributed to a random selection of horse owners in 2001 will provide prevalence data and also some population information about Australian horses. Volunteers from the questionnaire will then be enrolled in a cohort study in mid 2001. Animals will be monitored for up to two years and the incidence of Tying-Up in animals exposed or unexposed to certain risk factors will be compared. Concurrently a nationwide case-control study will be conducted through veterinarians to examine the difference in exposure to risk factors between diseased and non-diseased animals. The analyses of results from these studies should provide valuable information about the modifiable risk factors of Tying-Up among different groups of horses. In conclusion, we hope to provide an improved description of essential criteria for diagnosis of Tying-Up and a more logical approach to diagnosis and management of clinical cases. We also aim to produce a more effective treatment regimen that will minimise economic losses and suffering of affected horses. Finally we hope to achieve an overall reduction of prevalence of this condition through identification of modifiable risk factors of Tying-Up and their relative contribution to disease.


 

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:	Dr. David Evans
Organisation:	The University of Sydney Department of Animal Science SYDNEY NSW 2006
Phone:	(02) 9351 2474
Fax:	(02) 9351 3957
Email:	davide@doolittle.vetsci.su.oz.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	Over 400 two-year old horses have been enrolled in the first cohort of two-year old horses studied from August 2000. Over twenty horse trainers at Randwick, Rosehill, Warwick Farm and Newcastle have been involved in the study. Trainer compliance with the need for fortnightly records of speeds and distances of horse training and of racetrack usage has generally been excellent. Attrition of some stables has occurred during the year, but this has not threatened the viability or power of the study. The inclusion of carpal, tendon and fetlock injuries in the database has contributed to maintenance of trainer interest in the study. These additions to the scope of the study could enable future analyses of risk factors for causes of lameness other than shin soreness. Plans are now well advanced for enrollment of a new cohort of two-year olds from August 2001, as well as a new cohort of three year olds. A report of progress in the study will be presented at the International Horse Industry Symposium.


 

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

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 2020 SHEPPARTON VIC 3630
Phone:	(03) 5829 9566
Fax:	(03) 5829 9307
Email:	aom@mail.sheppnews.com.au
Objectives	· 1. 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. · 2. 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	Data analysed from the Australian Stud Book (Thoroughbred) courtesy of Dr. John Digby have revealed some interesting trends. Mare numbers have been dropping since 1985 but the number of breeding stallions has dropped such that there is a net increase in the number of mares per stallion. Breeding efficiency defined as live foal per mare bred has improved from ~40% in 1981 to almost 76% for the year 2000. Analysis of individual farm breeding records, although far from complete, has revealed some interesting differences between the Standardbred (SB) and Thoroughbred (TB) farms. Basically the pregnancy rates at the end of the breeding season were not different (97.3% v 93.6% at 15 days and 86.7% and 88.6% at 45 days). More twins were detected per pregnancy in the TB mares (13.8% v 3.5%). Loss rates of twins (to nothing) from 15 –25 days were higher in SB (7.1% v 3.7%). Number of breeds per cycle was 1.04 for TB v 2.21 for SB. Foal heat breeding resulted in a reduction of pregnancy rate for both breeds. Overall the fertility of TB mares was better than the SB when measured as pregnancy per cycle (70.4% v 62%). We concluded that the increased number of breeds per cycle, decreased pregnancy rates per cycle and increased embryonic loss of twins for the SB were all likely associated management procedures that were mostly mediated by economics. The similar end of season