Project Summary-Field Efficacy Study of Cisplatin Beads for the Treatment of Sarcoid in Horses The objective of this study is to determine the efficacy of treatment for cutaneous sarcoids in horses with cisplatin impregnated, slow release beads. Ten horses, client-owned, with spontaneously developing cutaneous sarcoids of < 3 cm diameter will be utilized. Gender, age, reproductive status and breed will be documented in the study. Horses will be examined prior to bead implantation to ensure that they are systemically healthy and there are no comorbidities. This will be determined by physical examination, serum chemistry analysis, complete blood cell count, and urinalysis with GGT/creatinine ratio. On Day 0, the sarcoid will be surgically excised, and the incision site will be implanted with up to 3 cisplatin- impregnated beads. The tissue removed will be stored in 10% buffered formalin and submitted for routine histopathological analysis. Horses will subsequently be monitored by routine clinical assessment as deemed appropriate by the treating clinician for the surgical site. At minimum, the surgical site will be reexamined at 10 days and 180 days, and the site documented by photograph. More frequent assessment may occur based upon clinical need. Success will be defined as no recrudescence of the sarcoid at that location within 180 days in greater than 50% of the treated horses. This success criterion is based upon the reported finding of a success rate of 30-50% of cases treated by surgical excision alone, in which “most tumors recurred within 6 months”.