With the spate of bisphosphonate articles hitting so rapidly, an overview is helpful. This class of drugs has been around since the 1800's. A main industrial use was to soften water in orange grove irrigation systems. Bone use in humans began in the mid 1990's (Fosamax). The first equine product (Tildren) was introduced in France in 2002. USA equine products (Tildren and Osphos) appeared in 2014. The newest products for humans are described as 20,000 times more powerful. Without getting into too much specific scientific detail, the affinity of bisphosphonates to bone is like metal chips to magnets. Once in the body, the drug quickly locks into bone.
Then there is this: "researchers are working to find them (bisphosphonates) in post-mortem bone samples – so far, those haven't yielded many answers."
Earlier I linked to a 2011 Canadian study measuring Tildren in bone:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3062923/
They administered the drug to 8 horses, and over a year's time they killed them (I am a bit uneasy about that), and then analyzed different bones for the drug. The study found the tuber coxae (TC) to be best site for biopsy. Interestingly, they found that the drug concentrations in bone did not diminish over the time studied, and the longest span (one year) maintained drug concentration. The report concludes that "there were no technical problems in measuring tiludronate in bone samples taken with a 5-mm diameter drill in the TC bone". I just do not understand why authorities are now getting no results. I can find no followup studies finding the assay technique used in 2011 to be unreliable; consider also, that there have been many human studies that had no difficulty measuring the drug in bones. This thread has shown the catastrophic difficulties for the entire industry, from drug makers to breeders to race tracks, should there be confirmation of bisphosphonates in equine bones. I cannot help but wonder if that is a factor in these biopsy assay difficulties.
