A widely-used arthritis medication for dogs, known as Librela, is now facing serious concerns following a review by the U.S. Food and Drug Administration (F.D.A.). This drug, which was approved for use last year, has been linked to alarming neurological side effects, including seizures, loss of muscle control, and even death in some cases.

Librela is an injection made from monoclonal antibodies designed to alleviate arthritis-related pain in dogs. While the product’s label initially listed mild side effects such as urinary tract infections and skin infections, disturbing reports from pet owners have surfaced. Many have noted that their dogs exhibited severe health issues shortly after receiving the injection, with some pets losing their ability to walk or stand, or tragically, losing their lives.

The F.D.A.'s investigation is based on over 3,600 reports of adverse events linked to Librela, although it did not definitively establish a causal relationship between the drug and the serious issues reported. It’s worth mentioning that the review serves as a warning system, revealing potential side effects that may not have been evident during initial clinical trials. As a result, the F.D.A. is advocating for updates to Librela’s labeling to inform pet owners about these risks.

Zoetis, the manufacturer of Librela, maintains that the drug is safe and effective, with a staggering 21 million doses distributed worldwide. Dr. Richard Goldstein, the company's chief medical officer, expressed his confidence in Librela, stating, “We at Zoetis — and I personally — stand 100 percent behind Librela as safe and effective.”

Veterinary experts, while recognizing the drug's benefits in improving mobility and the quality of life for many dogs, urge caution. Dr. Rory Todhunter, who leads the Richard P. Riney Canine Health Center at Cornell University, emphasized the importance of awareness for pet owners, highlighting that informed consent is crucial when it comes to medication risks.

The F.D.A.’s recent review has been hailed as a significant moment for pet owners who have faced devastating consequences after administering Librela to their dogs. Lita Dwight, co-executive director of Paws Over Profits—an advocacy group focused on raising awareness of the drug's potential dangers—discussed her heartbreaking experience after her miniature dachshund, Lacey, became gravely ill post-treatment. “As a pet parent, I want informed consent,” Ms. Dwight stated passionately.

Initially authorized in Europe in 2020, Librela's approval in the U.S. in May 2023 was met with mixed reactions as reports of severe side effects rapidly circulated on social media, with pet owners sharing both uplifting success stories and heart-wrenching accounts of loss.

Given that Librela is primarily prescribed to older dogs, many of which may already have health complications, pinpointing the exact cause of the reported adverse reactions poses a notable challenge. Dr. Todhunter acknowledged the complexities, stating, “Many older dogs have both arthritis and neurological diseases, making it challenging to differentiate the causes of symptoms.

Despite the confusion, the F.D.A. has identified several side effects reported more frequently in dogs treated with Librela compared to other arthritis medications, including muscle coordination loss, weakness, lameness, paralysis, and difficulty standing.

For concerned pet owners and veterinarians alike, the F.D.A. has urged the need for more comprehensive research to clarify the potential risks associated with Librela, especially for dogs with pre-existing neurological conditions. As discussions regarding their pets' health continue, the spotlight is on the ongoing safety and efficacy of this popular arthritis treatment.