According to the FDA Center for Veterinary Medicine, consult your veterinarian before using Vetsulin until further notice. A problem with the insulin product may cause instability, which may be dangerous, creating unpredictable fluctuations in glucose levels in diabetic patients. Vetsulin is the most common insulin product used for diabetic dogs, and it's also used for cats.
Meanwhile, according to the FDA CVM, "Your veterinarian should consider
transitioning their diabetic patients to other insulin products. In addition, FDA encourages veterinarians to report any adverse events."