The Breeders’ Cup Forum: Lasix – An International Veterinary Perspective
Brian Stewart is the head of Equine Welfare and Veterinary Services for Racing Victoria, the primary authority overseeing horse racing in the region of Australia that includes Melbourne. Formerly a private practitioner in Caulfield, Stewart was the head of Veterinary Regulation and International Liaison for the Hong Kong Jockey Club from 2002-2011. He has served as chairman of the International Group of Specialist Racing Veterinarians and in senior positions with the International Federation of Horseracing Authorities, among other roles in the industry.
This week’s Breeders’ Cup Forum with Stewart, conducted via email, is a counterbalance to the views of Southern California racetrack practitioner Don Shields, a staunch advocate for the race-day use of the anti-bleeding diuretic furosemide, or Lasix, to treat exercise-induced pulmonary hemorrhage. Shields was the subject of last week’s Forum, which can be read here.
Dr. Stewart made the following introductory comments prior to the Paulick Report’s questions:
I’d like to make a few points to explain why we will not consider the introduction of race-day furosemide medication in Australian (or Hong Kong) racing.
This is despite the fact that we acknowledge that furosemide does work to ameliorate EIPHS and is undoubtedly good for the individual horse that suffers significant EIPH, but we believe that its use would not be good for the business of racing, would not be good for the overall future good of the Thoroughbred breed and would not be good for the general Thoroughbred population because its use encourages/permits over-training and over-racing of horses.
—Furosemide has been clearly demonstrated to improve racing performance by means unrelated to its effect on EIPHS, that is by causing significant weight loss by the excretion of excess fluid. This effect has also been demonstrated to be inconsistent and unpredictable which must impact on the quality of the wagering product.
—There are suggestions and significant anecdotal reports that there is a degree of heritability associated with EIPHS. Until that possibility is disproved, there is significant risk for the overall quality and durability of Thoroughbred breed associated with breeding of horses that have been selected on the basis of performances assisted by furosemide.
—In my opinion, EIPHS is often associated with over-stressed horses, often with poor lung health (often associated with poor air quality and inflammatory airway disease. The occurrence of EIPHS detected by regular endoscopic examinations is a very good indicator that a horse is not coping with its workload/environment and is a warning sign to modify its training regime and attend to lung health problems. The use of furosemide may mask these warning signs and cause a horse to be over-worked and over-stressed leading to higher risk of injury.
—There is a philosophy that racing should be a test of the suitability and excellence of the individual for racing, both to identify the best athlete and to identify the best future breeding stock. If an individual is unsuitable for the purpose of racing, be it because of a susceptibility to EIPHS or a lack of durability or whatever, that individual’s best interests and the best interests of the breed and the industry are best served by removing that individual from the racing population.
—Every racing chemist I speak to outside of the USA, has absolutely no doubt that the use of race-day furosemide would interfere with their laboratory’s capability to detect prohibited substances. This fact alone is enough to cause us to have grave reservations about the introduction of race-day medication. It is interesting to note that WADA (World Anti-Doping Agency) classifies furosemide as a masking agent.
—Sudden death caused by EIPHS is extremely rare in Hong Kong and Australian racing and, when it does occur, is much more likely to have been caused by ventricular fibrillation than by the EIPHS syndrome.
How have horsemen in Hong Kong and Australia dealt with EIPH?
Horsemen manage EIPHS by regular endoscopic monitoring of horses in training, modification of the training regime, avoiding swimming horses, maintaining high air quality in stable, maintaining lung health by promptly and aggressively treating respiratory disease by the use of mucolytic, bronchodilators, vitamin c, and other supplement products.
Reducing gut fill prior to racing by withdrawing water and ‘soft feed’ for about four hours prior to racing is common and seems to have no adverse effects on horses…presumably by minimizing the ‘gut piston effect’ but possibly by causing mild dehydration and perhaps reducing pulmonary vascular pressures.
Horses that show reoccurring significant EIPHS are often retired from racing.
Are furosemide or other anti-bleeding medications used routinely in training? If so, when is the withdrawal time?
Furosemide and other diuretics are routinely used in training in Australia. Very few adjunct products, beyond commercial supplements, are used. The commonly used withdrawal period for furosemide is three days
Furosemide is not permitted for training in Hong Kong. This is primarily because of the importance placed on training performances by form analysts in HK and the opinion that training performances influenced by furosemide are an unreliable guide to race day performance and are therefore bad for business. The lung health of the vast majority of HK horses does not appear to be compromised by this ban on the use of furosemide in training.
When doing post-race endoscopic examinations, how often is a bleeding episode diagnosed as one that would affect performance?
Hong Kong statistics over about five years indicate that significant EIPHS (grade 3+/4+ on scope plus frank epistaxis) was assessed to be a contributing factor to poor racing performances in horses sent for veterinary inspections by the stewards in about 38% of these disappointing performances, which translated to about 1% of all runners.
Hinchcliff’s paper on the impact of EIPHS was based on post-race scopes done in Melbourne and may be referred to for information on the impact of EIPHS on performance.
Has there been any movement in Hong Kong or Australia to accept the widely held North American view that Lasix is good for the horse and that denying Lasix is borderline cruel to the animal?
There has been no significant movement in either HK or Australia (or Europe) to advance the position that denying Lasix is cruelty beyond the odd lobbying by trainers. There is no likelihood of race-day Lasix medication being introduced to Australian or HK racing.
Problem horses are either voluntarily or compulsorily retired from racing and the general consensus is that the welfare of horses is best advanced by not racing these horses that cannot adapt to the stresses of racing.
How are the American medication policies generally viewed where you have practiced?
American medication policies are generally regarded as being mistaken and bad for the business of racing and the overall health and safety of the entirety of the racehorse population and very risky for the future quality of the breed.
What medications are most often used in training in Hong Kong and Australia?
The standard racetrack medications used elsewhere in the world are used in both HK and Australia: NSAID (non-steroidal anti-inflammatory drugs), corticosteroids, HA (hyaluronic acid), pentosan, anti-ulcer medications, bronchodilators, mucolytics, etc.
What is the withdrawal time for phenylbutazone?
Approximately seven days.
Are intra-articular corticosteroids or Depo-Medrol administered routinely? Do you have any knowledge of how long the injection of corticosteroids suppresses the symptoms of pain?
Intra-articular corticosteroids are routinely administered. The suppression of inflammation by corticosteroids is not fully known and is the subject of considerable research work. A reasonable guess for triamcinoline acetonide might be approximately two weeks. Depo-Medrol is likely to be considerably longer but I do not have any reliable information on which to base an estimate.
We have shorter withdrawal times in North America for most of these drugs, yet seem to have more problems with soundness. I’ve heard American trainers say 1) trainers and veterinarians are using just as many or more drugs overseas but have substances that can’t be detected in tests; and 2) the testing standards are not nearly as high overseas as in North America. How would you respond to that?
Absolute rubbish. That said, there is always the possibility that ‘undetectable’ substances may be administered in racing anywhere in the world, although it must also be said that our trainers look to North America for the supply of the latest and best undetectable drugs.
The comments about low testing standards are incorrect and insulting to our laboratories.
Is any out-of-competition testing conducted in Australia or Hong Kong?
Yes. Hong Kong has a very intensive program. The Australian environment is logistically more challenging but there is a regular OOCT testing program which is being expanded. Recent incidents of the detection of attempts to illegally treat horses on race day in Melbourne racing have been the result of intelligence, surveillance and stable raids by compliance officers. This has been very successful and is an approach we will be expanding in the future. It is no longer possible to rely on laboratory testing alone to provide adequate doping and medication control.
What are the biggest challenges in the doping arena in Australia and Hong Kong?
I think the most significant challenge is the use of anabolic-like substances, for example peptide drugs, and blood-building drugs that are either undetectable, have very short detection times and are used to enhance the response to training by either building muscle mass or building blood parameters during training and are extremely unlikely to be detected in race day samples.
OOCT, intelligence, surveillance, stable raids, cooperation with police and customs perhaps combined with biological passports will be required to address these threats.