April 2, 2010 – CHICAGO (EWA) – A peer reviewed scientific study tracing race horses sent to slaughter for human consumption has found that 100% of the horses in the study group had been administered phenylbutazone, a banned carcinogen that can also fatally damage the bone marrow of humans. The findings appear to validate the European Union’s recent tightening of traceability requirements on horse meat from third countries.
The paper, titled Association of phenylbutazone usage with horses bought for slaughter: A public health risk, appeared in the journal Food and Chemical Toxicology and calls into question the reliability of the USDA (US Department of Agriculture) and CFIA (Canadian Food Inspection Agency) testing programs which have consistently failed to detect the substance.
The manuscript, which was authored by Drs. Nicholas Dodman, Nicolas Blondeau and Ann M. Marini, followed eighteen Thoroughbred (TB) race horses that were identified by matching their registered name to their race track drug record over a five year period and were given phenylbutazone (PBZ, Bute) on race day and were subsequently sent to slaughter for human consumption.
The study also traced records on sixteen TB race horses that were given PBZ on race day and would have also entered the food chain had they not been rescued. The study was limited to race horses because of the availability of drug records, but phenylbutazone is one of the most common drugs used in the treatment of musculoskeletal injuries in horses.
Because of the bone marrow toxicity caused by PBZ in humans, the Food and Drug Administration (FDA) has set no safe levels of PBZ and bans its use food producing animals, including horses. While PBZ is but one of the numerous banned substances that are routinely given to US horses, it is one of the most dangerous.
Defenders of horse slaughter have long pointed to USDA testing records which consistently showed no positive results for PBZ. The new study shows that the USDA testing could not have been accurate. Indeed, the study uncovered a pilot test performed by the USDA in 2004 and 2005 that used a different testing technique and found 8.3% of the meat to be contaminated with PBZ. The pilot program had been subsequently discontinued.
The study estimates that sixty seven million pounds of horse meat derived from US horses were sent overseas for human consumption in 2008. If 8.3% of this meat contained phenylbutazone residues, it would translate to over 5 million pounds of contaminated meat.
Opponents of horse slaughter have long warned that US horses are not raised as food animals and mechanisms to ensure the removal of horses treated with banned substances from the food chain are inadequate at best.
Equine Welfare Alliance recently issued a discussion paper with their partners, Canadian Horse Defence Coalition on the serious drug issue concerning North American horses. The comprehensive paper covers concerns over the ability to meet compliance with European Commission regulations on food safety.
Article is cited as, Dodman, N., Blondeau, N., Marini, A.M., Association of phenylbutazone usage with horses bought for slaughter: A public health risk, Food and Chemical Toxicology (2010), doi: 10.1016/j.fct. 2010.02.021
Tufts University, Cummings School of Veterinary Medicine, North Grafton, MA
Institut de Pharmacologie Moléculaire et Cellulaire – I.P.M.C, UMR 6097,
C.N.R.S/Université de Nice Sophia Antipolis, 660 route des Lucioles, Sophia Antipolis
06560 Valbonne, FRANCE
Department of Neurology and Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD.
The Equine Welfare Alliance is a dues free, umbrella organization with over 100 member organizations. The organization focuses its efforts on the welfare of all equines and the preservation of wild equids.