FDA WARNING_LETTER - Ridley USA Inc. - April 01, 2026

Ridley USA Inc., located in Iowa City, Iowa, received an FDA Warning Letter following an inspection conducted from September 2 to September 17, 2025. The investigation was prompted by a report of at least 16 cattle deaths caused by a medicated feed mix-up. The company mistakenly included the drug monensin in a cattle feed instead of the intended medication, leading to a voluntary Class I recall in August 2025.

The FDA identified several significant violations of the Federal Food, Drug, and Cosmetic Act, specifically regarding Current Good Manufacturing Practice (CGMP) and Hazard Analysis and Risk-Based Preventive Controls for animal food (21 CFR Parts 225 and 507). Key issues included a failure to accurately assess the risk of operator errors during ingredient addition and a failure to properly identify and control drugs in mixing areas. Additionally, the facility failed to conduct mandatory daily reconciliations between actual and theoretical drug usage, which prevented the company from catching the inventory discrepancy before the contaminated feed was distributed.

While Ridley USA Inc. has proposed corrective actions—including updated software and employee training—the FDA found their responses insufficient due to a lack of supporting documentation and validation records. The company must provide a written response within 15 working days detailing specific steps taken to correct these violations and prevent their recurrence. Failure to address these concerns may result in further regulatory or legal action.