FDA Investigates Contaminated Veterinary Product Linked to Horse Infections and Deaths

On September 29, 2026, the U.S. Food and Drug Administration (FDA) issued warning letters to Neogen Corporation and Sciarra Aeromed Inc. following an investigation into contamination linked to Neogen Vet HYCOAT (hyaluronate sodium sterile solution), a veterinary wound care product. This product, labeled as sterile, has been associated with serious infections and at least 20 horse deaths, marking the largest number of fatalities from a quality defect in an FDA-regulated veterinary product.

The reported deaths reflect only those documented to the FDA, and the total number of affected horses includes only unique cases confirmed by the agency. As of now, the FDA has not received final outcome reports for many horses affected by the injuries.

The FDA's investigation revealed fungal contamination in HYCOAT, despite its label asserting sterility. Fungi identified in the product include Purpureocillium lilacinum, Paraisaria heteropoda, Gongronella lacrispora, Purpureocillium sodanum, and Isaria takamizusanensis. Reports indicate that nearly 100 horses suffered serious joint infections after administration of the contaminated product, with at least 20 having to be humanely euthanized after treatments failed. Purpureocillium lilacinum is particularly resistant to antifungal medications, complicating treatment efforts.

The investigation encompassed extensive reviews of epidemiological and clinical data, as well as inspections of the manufacturing facility, which revealed serious violations, including the production of sterile-labeled products in insanitary conditions.

This situation highlights the critical need for reporting adverse events related to veterinary products. Neogen marketed HYCOAT as a veterinary device but failed to proactively report adverse events to the FDA. It was the voluntary reports from veterinarians that prompted the FDA's investigation. The agency urges all companies, veterinarians, and animal owners to report any adverse events and quality concerns, as timely reporting can facilitate quicker investigations and public alerts. For more information on how to report issues, visit the FDA's webpage on reporting animal drug and device side effects.