Pet owners and horse owners across the country are being told to immediately stop using a pair of joint medications after glass fibers turned up floating inside vials meant for injection, American Regent announced last Friday. The company has recalled two lots of Adequan Canine and two lots of Adequan i.m., the horse version of the drug, after workers found fiberglass during testing. No injuries have been reported so far, but federal regulators are urging veterinary clinics and pet owners to check their medicine cabinets for the affected lots right away.
According to OregonLive.com, recalled Adequan Canine lot 3369 is a 100 mg/mL formula packaged in 5 mL multi-dose vials that was first distributed May 22, 2024. Recalled canine lot 25011 carries the same 100 mg/mL formulation and went out starting April 14, 2025. The two recalled Adequan i.m. lots for horses are 25265P, a 500 mg/5 mL single-dose vial distributed starting Jan. 22, and 24416, distributed starting May 8, 2025.
Lot 3369 expires Oct. 31, 2026, while lots 25011, 25265P and 24416 don't expire until 2027, the outlet reports. The affected vials were shipped to online pharmacies, distributors, wholesalers and veterinarians across the United States, according to the same report.
What's Floating Inside the Vials
American Regent discovered the glass fibers during routine testing of retained sample vials, according to the FDA's recall notice. The recalled products are typically clear, colorless to slightly yellow solutions, per the FDA. Particulate matter in an intramuscular injectable can cause local irritation, swelling, inflammation, injection-site pain, infection or abscesses, the agency warns.
A Manufacturing Plant With a History of Particulate Problems
American Regent's Animal Health division is headquartered in Shirley, New York, and operates as a U.S. manufacturing subsidiary of Tokyo-based Daiichi Sankyo Company, having previously operated under the name Luitpold Pharmaceuticals, according to the Town of Brookhaven IDA. Luitpold consolidated its subsidiaries under the American Regent name in January 2019.
The Shirley plant isn't new to particulate complaints. The FDA issued a formal warning letter to Luitpold Pharmaceuticals in September 2011 over persistent particulate matter and glass delamination at the facility, as reported by Pharmafile. The resulting factory renovations forced a total production halt in 2012 and 2013, triggering a nationwide Adequan shortage that pushed veterinarians toward alternative therapies, according to DVM360.
Glass Particulates Are a Known Hazard in Injectable Drugs
Foreign particulate matter such as glass fibers from container friction or vial delamination is a leading cause of sterile injectable drug recalls, historically accounting for more than 20% of parenteral drug recalls industry-wide, per Cleanroom Technology. The FDA classifies recalls like this one, involving glass particulate contamination in intramuscular injectables, as Class II, meaning exposure may cause temporary or medically reversible harm rather than a life-threatening injury, Pharmacy Times notes.
Why There's No Easy Substitute for Adequan
Adequan's active ingredient, polysulfated glycosaminoglycan, is a compound derived from bovine tracheal cartilage that functions as the only FDA-approved disease-modifying osteoarthritis drug marketed to slow cartilage breakdown in dogs and horses, according to DailyMed. Adequan Canine injections are used to treat joint dysfunction in dogs, while Adequan i.m. treats joint dysfunction and lameness in horses, with both administered as intramuscular shots, the outlet reports.
What Pet Owners and Vet Clinics Should Do Now
The FDA is urging consumers to immediately stop using the recalled products and either throw them away or return them to the manufacturer. Pet owners and veterinary clinics holding the affected lots can contact American Regent customer service by phone at 800-645-1706 or by email at [email protected] to arrange a replacement or credit.
Distributors, retail pharmacies and veterinary clinics holding any of the four recalled lots are instructed to quarantine their remaining stock and contact American Regent's dedicated pharmacovigilance line at 888-354-4857 to arrange returns, according to RecallTimes. Veterinarians and pet owners who notice adverse reactions can also report them to the FDA's Center for Veterinary Medicine using Form 1932a or by calling 1-888-FDA-VETS.
