Treatment for arthritis in dogs is under fire after reports of serious and even fatal side effects

A common arthritis medication for dogs may be more dangerous than we knew. This week, the Food and Drug Administration reported several serious adverse events and deaths associated with the recently approved drug Librela.

On Monday, the FDA’s Center for Veterinary Medicine Issued A letter to veterinarians detailing the results of their investigation into Liberella. The Food and Drug Administration has identified several serious adverse effects associated with its use, including seizures and loss of muscle function. Many dogs have reportedly died or been euthanized due to these complications. The agency recommends that the drug maker update its labeling to include these potential side effects, and advises veterinarians and the public to report any adverse events associated with its use.

Active ingredient Librela, bedinfitmap, It is an antibody manufactured in a laboratory by Zoetis. In 2023, the F.D.A consent To treat osteoporosis in dogs. The drug—delivered by injection once a month—targets and blocks a protein involved in pain regulation called canine nerve growth factor (NGF). The medication is designed to lower NGF levels, which tend to be higher in dogs with osteoporosis. It is the first monoclonal antibody-based drug approved for dogs, and the second ever approved for pets.

At the time of its approval, some of the most common side effects associated with Librela were certain types of infections (urinary tract infections, bacterial skin infections), rashes, vomiting, and weight loss. As is customary with every approved drug, the FDA monitored reports of adverse events associated with Librela submitted by patients and physicians. Some dog owners have reported very serious — and even fatal — symptoms in their pets after they started taking Liberella.

According to the FDA, there were 3,674 reports of adverse events related to Librela, as of March 2024. These adverse events were more common among older dogs, which makes sense given that age is a common risk factor for osteoarthritis. The US Food and Drug Administration (FDA) has identified several potentially serious adverse events that are not currently included in the drug’s classification as a potential side effect. These include ataxia (poor muscle control), seizures, diarrhea, and paralysis. In some cases, dogs have died or been euthanized shortly after suffering these serious events.

In one report, for example, a 10-year-old boy from the Great Pyrenees became ataxic an hour after taking Liberella. Within a day, the dog developed urinary incontinence and lameness in the hind limbs, which eventually spread to the dog’s forelimbs. Within two days, the dog was paralyzed. Four days after taking the medicine, the dog died.

The FDA is careful to note that these adverse events have not been conclusively linked to Librela yet. At the same time, the agency rejected the idea, put forward by Zoetis, that the large number of drug-related reports were simply caused by negative publicity on social media.

“There is no evidence that the reported cases are not true cases associated with Librela,” the agency wrote in its report. review From these reports.

Zoetis issued a statement After the FDA letter. The company criticized some media coverage for mischaracterizing the FDA communications as a “warning,” rather than an “informational update” intended to educate veterinarians and the public. The company also claimed, based on data from the European Union, that any specific adverse event associated with Librela is likely to be rare.

“We remain confident in the safety and effectiveness of Librela and are committed to supporting veterinarians and pet owners in helping dogs live with less pain and greater mobility,” the company said in its statement.

It will take more time and research to confirm these serious side effects. But in the meantime, the FDA has recommended that Zoetis update its labeling for Librela to list these potential adverse events (the Center for Veterinary Medicine itself cannot mandate changes to safety-related labels).

While Zoetis stands by its drug, it said it was discussing potential labeling changes with the FDA. The FDA also advises dog owners and veterinarians to continue reporting adverse events associated with the use of the drug.