The Device Gap: Inside the FDA's HYCOAT Warning Letters

On September 29, 2026, the U.S. Food and Drug Administration announced warning letters to Neogen Corporation and Sciarra Aeromed, Inc. after fungal contamination was found in Neogen Vet HYCOAT, a hyaluronate sodium solution sold for veterinary use. The agency linked the product to serious joint infections in nearly 100 horses and reported that at least 20 of them were humanely euthanized after treatment failed. The FDA describes the episode as the largest number of horse deaths ever associated with a quality defect in an FDA regulated veterinary medical product.

The agency adds a caution that matters for anyone trying to size the damage: the totals reflect only deaths reported to the FDA, and it has not been told the final outcome for many of the injured horses. The published figure is a floor.

What the Warning Letter Documents

The warning letter to Neogen, dated September 23, 2026, cites "over 95 individual cases." Testing of lot 5A001 found viable fungal contaminants, and the FDA's public update names five species, among them Purpureocillium lilacinum, which the agency calls "particularly resistant to antifungal drugs." In the FDA's words, "Fungi introduced into a joint can cause infection, tissue destruction, and systemic illness."

Inspectors who visited the contract manufacturer's facility reported insanitary conditions for a product labeled sterile. The cited gaps include no sporicidal cleaning agent, no monitoring of differential pressure, and no viable particulate or personnel sampling. The letter classes the product as both adulterated and misbranded.

A Topical Product in an Injectable Vial

HYCOAT is labeled as "a sterile topical wound management solution intended for use on surgical wounds, burns, and similar conditions." It is nonetheless packaged in a septum-top glass vial, the same style used for sterile injectable drugs, and the FDA began receiving reports in late 2025 from veterinarians who had injected it. The warning letter states that HYCOAT is used off-label as a joint injection and that "your labeling does not contain any limitations, warnings, or contraindications pertaining to this use."

That detail is the one hunter/jumper owners should sit with. Joint injection is common enough that the studies cited below count it in the hundreds of thousands, and the product on the other end of the needle is chosen by the veterinarian. FDA-approved hyaluronate products exist for the purpose: Boehringer Ingelheim describes its Legend as FDA approved for both intravenous and intra-articular administration, with the intra-articular route limited to the 2 mL (0.07 fl oz) presentation for the carpus or fetlock, and the 4 mL (0.14 fl oz) and 20 mL (0.68 fl oz) presentations intravenous only. Approval of one hyaluronate product for the joint says nothing about another.

The Manufacturer's Case, and Where It Runs Out

Neogen's position deserves a fair statement. When it announced a voluntary nationwide recall on January 28, 2026, the company said it had received several reports of adverse events in horses after intra-articular injection, which it described as inconsistent with the labeled use, and that it had received no adverse event reports when the product was used as labeled. A manufacturer is not ordinarily answerable for every off-label decision a clinician makes, and that argument has real force.

A sterile solution in a septum-top vial, with no warning against the needle, is a labeling decision as much as a clinical one.

The FDA's reasoning goes further than the off-label defense can reach. The agency states that Neogen marketed HYCOAT as an animal device and did not proactively report adverse events to the FDA, and that the agency learned of the problem only because veterinarians contacted it directly. The recall itself covered 28 in-date lots: 24 lots of the 2 mL (0.07 fl oz) vials and 4 lots of the 10 mL (0.34 fl oz) vials. Eight months passed between that January notice, which spoke of "several" reports, and a September letter citing more than 95 cases. The two documents describe different stages of an investigation, but an owner reading the recall notice in the winter had no way to see the scale that was coming. The letter gives Neogen fifteen working days from receipt to respond in writing.

The Baseline Risk Is Low, Which Is the Point

Joint infection after injection is a known and measured complication even when everything goes right. A 2013 study in the Australian Veterinary Journal by Steel and colleagues followed 16,624 injections in Thoroughbred racehorses and found 13 septic joints, about 7.8 cases per 10,000 injections. A 2016 survey of equine veterinarians in Veterinary Surgery, by Gillespie, Adams, and Moore, drew on records of 319,760 injected joints and counted 67 that became septic, or 2.10 per 10,000. Both groups of authors describe the complication as uncommon.

Those numbers set the baseline: even careful practice carries a small risk, and a contaminated vial adds a risk that no technique can remove, because the solution in the syringe is the source. In the FDA's account, the contamination was found in the product itself.

What a Barn Should Record Now

None of this requires an owner to second-guess a veterinarian's clinical judgment. It requires the barn to keep the kind of record that makes a recall actionable, since the recalled lot numbers in this case were public and an owner with no injection log could not have checked them.

The sport spends considerable attention on what sits in a horse's mouth and on its nose. The HYCOAT letters are a reminder that the supply chain behind the syringe deserves the same scrutiny, and that owners are the only people in the barn who can insist the lot number gets written down.