FDA Issues Warning Letters to Neogen Corp. Following Horse Deaths Linked to HYCOAT

The U.S. Food and Drug Administration (FDA) has issued warning letters to Neogen Corporation and Sciarra Aeromed, Inc. after an investigation into the veterinary product Neogen Vet HYCOAT, which has been linked to serious infections and the deaths of horses. Federal investigators have found that nearly 100 horses developed severe joint infections after being treated with the hyaluronate sodium solution, a product marketed as sterile for wound management. At least 20 horses were euthanized following unsuccessful treatment attempts.

In January 2026, Neogen voluntarily recalled HYCOAT nationwide. The FDA remarked that this incident represents the highest number of reported horse deaths associated with a quality defect in a veterinary medical product, and it marks the largest number of fatalities attributed to microbial contamination of an FDA-regulated product advertised as sterile.

The FDA stated that the reported figures may not encompass all affected cases, as only those with sufficient identifying information were included. The final outcomes for a number of horses remain unknown.

HYCOAT is intended for topical management of surgical wounds and similar injuries; however, it is packaged in a glass vial resembling those used for injectable medications. Reports began surfacing in late 2025 regarding the product being administered via injection by veterinarians. Laboratory testing revealed several fungal organisms, including Purpureocillium lilacinum and others, present in the product. Introducing such organisms into a joint can lead to severe infections and systemic disease, with some strains resistant to antifungal medications, complicating treatment.

The FDA found serious violations at the manufacturing facility, including the production of sterile-labeled products under unsanitary conditions. Veterinarians played a crucial role in bringing the issue to the FDA’s attention, as Neogen did not proactively report adverse events related to HYCOAT. Reports from veterinarians prompted a broader investigation that uncovered further cases and contamination acknowledgment.

The FDA urges veterinary professionals to report any adverse events or product-quality concerns related to veterinary products. This early reporting can assist regulators in identifying patterns and addressing potential safety issues before more animals are harmed.