How many ex-racehorses end up at the knackery? This is a hotly-debated question at the moment, and has been the subject of some close research on my part in the past few weeks. This is going to be a two-part post. Today, I will look at the estimates that have been widely disseminated by the media, particularly in recent weeks, and point out why they are an exaggeration.
Like many others, including journalists, I have previously used the figures cited by the Coalition for the Protection of Racehorses regarding how many horses are sent to the knackery by the racing industry (which have changed in the years since I first came across them, when they cited a figure of 18,000). This was calculated on the assumption, widely disseminated, that only 30% of foals born actually make it as far as a race. On the basis of this, the CPR currently state that ‘approximate[ly] 10,000 [foals] will be ruthlessly discarded and mostly end up at “the doggers.”’ 
Unfortunately, in calculating this figure, the CPR have cited research that itself represents a misreading of the original studies. Up until this year, the only formal research in this area was done by Ariella Hayek, who in her 2004 thesis included the statement “A widely accepted figure is that only 300 of 1000 Thoroughbred foals born actually end up racing” . Hayek here references studies by both Bourke and Bailey. I have not read the Bourke paper in its entirety, as I have not been able to locate a copy, however apparently the original reference reads “…in any one year, 1000 mares produce about 300 foals who finally race.”  There is no reference to the number of foals born from 1,000 mares. The 1995 Bailey paper (which I have read) states “of the progeny of 1000 mares, about 300 horses start in a race.”  Which is somewhat ambivalent in its wording, and easily misconstrued, which I believe is what happened with Hayek.
In fact, an accurate determination of the number or percentage of horses who do eventually race is hard to make, given that there are statistics for horses who are born, and statistics for those who are registered (horses who remain unregistered are not counted in industry statistics, as they are not considered racehorses), but, as horses can be registered at any age it’s not a simple sum to work out the difference. Fortunately, I’m married to a trained statistician, who has extrapolated from the data in the Australian Racing Fact Book to come up with the following estimates covering recent years:
|RACING YEAR||AUSTRALIAN-BORN* HORSES REGISTERED||NUMBER OF HORSES NOT REGISTERED||PERCENTAGE UNREGISTERED|
*allowing an estimate of 4% for overseas-born registrations
Please note, this table only represents horses who are unregistered. There are horses who are registered, who then don’t go on to race. However, you can see from this table that the figures disseminated in the media regarding the number of horses who don’t make it to the track (and who, the subsequent assumption is, all end up at the knackery) are clearly wrong.
On the other hand, because these unregistered horses don’t count in industry statistics, it is hard to ascertain exactly what happens to them. While I don’t believe every single one ends up as pet food, I also doubt that they all find happy ‘forever’ homes. The truth probably lies somewhere in the middle. The fact that they are discounted from industry statistics is problematic, as the fate of these horses is subsequently open to speculation, and can be construed according to the agendas of either pro- or anti-racing groups.
Next week, I will look at the only peer-reviewed study to be published on this issue, as well as some of the dubious figures being offered by the racing industry.
 ‘Wastage’, Coalition for the Protection of Racehorses page, accessed 3 December 2014 http://www.horseracingkills.com/the-issues/wastage/
 Hayek, Ariella. “Epidemiology of Horses Leaving the Racing and Breeding Industries.” Bachelor of Science (Vet Science) thesis, University of Sydney, 2004.
 Facebook post by Coalition for the Protection of Racehorses – Exposed dated 29 October 2014, accessed 27 November https://www.facebook.com/521074617973062/photos/pcb.752493831497805/752493434831178/?type=1&theater
 Bailey, CJ, RJ Rose, SWJ Reid, DR Hodgson, ‘Wastage in the Australian Thoroughbred Racing Industry: a survey of Sydney trainers,’ Australian Vet Journal (75), 1997, p.64.