440 Scientific Reports JAVMA, Vol 236, No. 4, February 15, 2010 EQUINE T he Keeneland September yearling sale is typically the largest sale in the yearling Thoroughbred mar- ket. In the past 12 years, the number of horses sold has increased from 2,949 in 1996 to 3,605 in 2008, while median value increased from $22,000 to $37,000. 1 For many years, the economic value of Thoroughbred year- lings offered for sale as future racehorses has been in- fluenced by their pedigree and conformation. Recently, prospective buyers have paid increasing attention to the health status of yearlings, with emphasis on the results of presale radiographic examinations, a history of pre- sale arthroscopic surgery, and the results of endoscopic evaluation of the upper airway. Prevalence of various presale radiographic findings and association of findings with sales price in Thoroughbred yearlings sold in Kentucky Stephanie A. Preston, MSc; Dana N. Zimmel, DVM, DACVIM, DABVP; Terese L. Chmielewski, PT, PhD; Troy N. Trumble, DVM, PhD; Murray P. Brown, DVM, MSc; Joseph C. Boneau, DVM; Jorge A. Hernandez, DVM, MPVM, PhD Objective—To estimate prevalences of various presale radiographic findings and of presale arthroscopy in horses offered for sale at the 2006 Keeneland September yearling sale and to compare sales prices between yearlings with and without various presale radiographic findings or a history of arthroscopy. Animals—397 Thoroughbred yearlings. Design—Cross-sectional study. Procedures—Presale radiographs and health records were examined to estimate preva- lences of various radiographic findings and presale arthroscopy. Sales price records were used to compare sales prices between yearlings with and without various presale radio- graphic findings or a history of arthroscopy. Results—In the forelimbs, the most common radiographic findings were vascular channels in the proximal sesamoid bones (23%), enthesophytes or osteophytes in the radiocarpal joint (22%), and osteochondritis lesions involving the sagittal ridge of the third metacarpal bone (20%). In the hind limbs, the most common radiographic findings were entheso- phytes or osteophytes involving the proximal sesamoid bones (39%), abnormalities of the distodorsal aspect of the third metatarsal bone (36%), enthesophytes or osteophytes in- volving the distal intertarsal joint (27%), and osteochondritis lesions involving the stifle joint (8%). Thirteen percent of horses had a history of presale arthroscopy. Median sales price was significantly lower in horses with fragments of the proximal phalanx than in horses without. Median sales price was significantly higher in horses with a history of presale arthroscopy than in horses without. Conclusions and Clinical Relevance—Results revealed significant associations between a diagnosis of fragments of the proximal phalanx, presale arthroscopy, and sales price in Thoroughbred yearlings. (J Am Vet Med Assoc 2010:236:440–445) In the Thoroughbred industry, there is a percep- tion that results of presale radiographic examinations affect the sales price of yearlings. Objective data on the prevalence of presale radiographic findings and presale arthroscopy, and the association of these factors with the sales price of yearlings may help guide sales deci- sions and the subsequent management of yearlings in training. 2 Current knowledge of the prevalence of vari- ous radiographic findings in Thoroughbred yearlings offered for sale is limited. In a study 3 of 1,162 horses offered for sale in Kentucky between 1993 and 1996, vascular channels in the proximal sesamoid bones of the forelimbs (98% of horses) and hind limbs (93% of horses) were the most common radiographic findings. However, study horses were not randomly selected. In From the Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610- 0136 (Preston, Zimmel, Brown, Hernandez); the Department of Physical Therapy, College of Public Health and Health Professions, University of Florida, Gainesville, FL 32610-0154 (Chmielewski); the Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108 (Trumble); and 696 Providence Rd, Lexington, KY 40502 (Boneau). Supported by the University of Florida Equine Soundness Program. The authors thank Katherine Henry and Derah Hubbart for technical assistance. Address correspondence to Dr. Hernandez (hernandezj@vetmed.ufl.edu). ABBREVIATIONS CI Confidence interval MC3 Third metacarpal bone MCP Metacarpophalangeal MT3 Third metatarsal bone MTP Metatarsophalangeal OCD Osteochondritis dissecans P1 Proximal phalanx