**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** WIDESPREAD OFF-LABEL USE OF BISPHOSPHONATES TO ALTER BONE DEVELOPMENT IN YOUNG HORSES IS COMMON IN THE EQUINE INDUSTRY, HOWEVER THE EFFECTS OF THESE DRUGS HAVE NOT BEEN TESTED IN HORSES OF THIS AGE. THIS PRACTICE MAY CONTRIBUTE TO THE EARLY BREAKDOWN OF YOUNG HORSES, WHICH, BEYOND BEING A MAJOR CONCERN FOR ANIMAL WELFARE, MAY ALSO PUT THE HEALTH AND SAFETY OF JOCKEYS IN DANGER. THE GOAL OF THE WORK IS TO DETERMINE THE EFFECTS OF BISPHOSPHONATE USE ON BONE AND JOINT HEALTH IN YOUNG HORSES UNDERGOING EXERCISE THROUGH THE USE OF A HORSE AND SHEEP MODEL. SPECIFICALLY, TO DETERMINE THE CLEARANCE OF BISPHOSPHONATE FROM THE BLOODSTREAM IN YOUNG HORSES/SHEEP, DETERMINE THE TIME COURSE OF INFLUENCE AND EFFECTS OF BISPHOSPHONATES ON BONE DEVELOPMENT, AND DETERMINE THE EFFECTS OF BISPHOSPHONATES ON CARTILAGE WHEN SUBJECTED TO AN INFLAMMATORY INSULT. WE EXPECT THAT YOUNGER ANIMALS WILL CLEAR BISPHOSPHONATES FROM THEIR SYSTEM FASTER THAN ADULT HORSES, THAT BONE DEVELOPMENT WILL BE COMPROMISED LEADING TO EASIER BREAKDOWN, AND THAT BISPHOSPHONATES WILL HAVE ANTI-INFLAMMATORY EFFECTS IN THE JOINT. THIS RESEARCH WILL CREATE KNOWLEDGE TO DRIVE FUTURE RESEARCH REGARDING THE USE OF BISPHOSPHONATES IN YOUNG HORSES AND WILL PROVIDE EVIDENCE UPON WHICH NEW REGULATORY POLICIES FOR THE USE OF BISPHOSPHONATES IN YOUNG HORSES WILL BE BASED.