Common Malignant Spontaneous Neoplastic Findings in SD Rats Used in Nonclinical Research Studies

STP 2022 -- Sprague Dawley (SD) rats are commonly used in toxicologic pathology studies and frequently the rodent choice for two-year (104-week) carcinogenicity studies. It is important to accurately identify rare and common spontaneous neoplasms for proper assessment of the carcinogenic potential of the test article in such studies. A previous study published on SD rat background neoplastic findings was last completed in the year 2017 (Weber et al., 2017) and hence, an update on the current trend on incidence and range of spontaneous malignant neoplastic lesions in SD rats will be valuable for toxicologic pathologists.