Concerns about Salix’s performance-enhancing attributes may pale in comparison to the potential detrimental effects the drug’s widespread use in North America may have on the genetic health of the Thoroughbred.

The heritability of exercise-induced pulmonary hemorrhaging (EIPH), commonly known as bleeding, came to light during a veterinarian panel discussion as part of the public session of the two-day International Summit on Race Day Medication, EIPH and the Racehorse at Belmont Park in Elmont, N.Y.

South African-based international veterinarian John McVeigh, BVMS, MRCVS, said the genetic connection of EIPH was made in a study completed back in 2004 called "A genetic analysis of epistaxis as associated with EIPH in the Southern African Thoroughbred."

"The relationship between runners with EIPH and the stallion has a heritability of 0.4, which is very high," McVeigh said during the panel discussion. "The two sires that produced the most bleeder progeny were both champion sires