We are aware that there has been some recent concerns about the use of Librela for the treatment of osteoarthritis and its safety. We thought it may be helpful to provide some information as to when and why it has been used, and what updated information we have with regards to its safe use.
Osteoarthritis
Osteoarthritis, similar to humans, affects many dogs, cats and other species. It is a complex disease with multiple causes. The wear and tear of joints can be age-related (especially in our overweight pets), due to prior injury, infection, it can be an immune mediated issue and even as a result of developmental abnormalities, predisposing our younger pets to an earlier onset (such as hip and elbow dysplasia).
When it comes to taking care of our arthritic pets, our main goals are to reduce their pain, maintain their joint health, their mobility and thus, their quality of life. When your dog is showing signs of arthritis, whether that be obvious issues with their mobility or more subtle changes to behaviour, we will always start with a thorough examination and discussion with you. Depending on your pet: their breed, age, weight, how quickly it began, history of trauma and the examination itself – all of these factors will normally determine the course of action. We may discuss imaging the joints with you if we feel it may be warranted to gather more information or confirm a diagnosis.
As veterinarians, we will always tailor the treatment plan to the pet and our client’s needs. In any condition, our treatment is based on medical knowledge, and comparing the risks and benefits of any medication or procedure to the ultimate goal of – either curing the disease, or making your pet as comfortable as possible. In terms of treatment for osteoarthritis, the options are wide-ranging including pain medication, weight management, over-the-counter joint supplements, physiotherapy and surgery in select cases. In most cases, these remedies are used in tandem due to the complexity of arthritis itself.
What is Librela?
Now lets talk about Librela. It is a monthly injection we have used to treat the pain caused by osteoarthritis in dogs. It was introduced to the European market in February 2021. Since then, Zoetis has reported that 21 million doses have been distributed globally, helping millions of dogs lead a more comfortable life.
It’s effectively an antibody, which is specifically designed to bind to and eliminate something called the Nerve Growth Factor (NGF). NGF, is a protein which is involved in nerve function, and is associated with the pain stimulus or sensation in arthritic dogs. By extension, if Librela binds to the NGF and prevents the sensation of pain, this will lead to pain relief for the treated dog.
Librela, Studies and its Safety
Prior to its introduction to the market, as is standard for any medication, safety and efficacy studies were conducted in the US and EU. They demonstrated a reasonable safety profile and efficacy in the dogs treated, usually after 2 monthly doses were administered. However, as with all drugs used in veterinary medicine, safety and efficacy monitoring does not end when a medication is introduced to the market. The safety of all drugs used in the veterinary market in the UK is continually assessed by a regulatory body, the Veterinary Medicines Directorate (VMD). The VMD uses feedback on drug use from owners, veterinary surgeons and the pharmaceutical manufacturers, to survey the effect and safety of the drugs while being used in the market.
As such, the list of potential adverse reactions maybe linked with Librela has been updated as of 2025:
- Balance problems or trouble walking
- Weakness or trouble standing
- Paralysis
- Seizures
- Drinking more
- Urinating more
- Loss of bladder control
- Vomiting or diarrhoea
It’s important to note that Zoetis (the manufacturer) has issued a statement regarding the above adverse reactions dated 18th December, 2024:
“With over 21 million doses distributed globally, no individual adverse event sign has been reported at a rate higher than rare, as defined by the European Medicines Agency (EMA) – representing less than 10 occurrences per 10,000 treated animals.”
In addition to this, a veterinary-specialist led review of mobility adverse reactions of Librela was conducted and published on the 9th of May 2025. The study highlighted a potential ninefold increase in reports of unexpected lameness or mobility concerns after Librela was introduced to the market.
However, the study noted the limitations of associating Librela with these reports in dogs with concurrent underlying issues such as arthritis or pre-existing conditions. In short, they felt there was a far higher level of reported side effects than they would have expected and that has been reported in the use of other drugs, but they couldn’t look at each individual report to verify a definite link to Librela use. For example, if an arthritic dog jumped off a sofa and presented with lameness to a vet and the case was reported, this would be included in their study.
Furthermore, the study did caution and highlight the need for continuous surveillance of its usage. The main point of contention being that in humans, the inhibition of the Nerve Growth Factor (NGF) was linked to accelerated joint degeneration in some cases during clinical trials, resulting in a syndrome known as rapidly progressive osteoarthritis. It is important to note that this has not been conclusively demonstrated in dogs yet.
So, is Librela safe to use in my dog?
Ultimately, it has been used safely and effectively in many of our patients and the frequency of side effects reported to it are still rare. However, this does not mean there are no adverse reactions associated with it. As mentioned earlier, we always assess the risk and benefit to each, individual patient.
Most of our arthritic dogs are started on first line pain medications, such as anti-inflammatory drugs; Paracetamol (dog specific), off licence human medications and a range of other drugs in combination with appropriate interventions such as weight management and physiotherapy. However, every drug has its own set of potential adverse reactions, and in those cases, Librela has risen as an effective alternative management of osteoarthritis for some of our older patients, especially where other drugs have proven to not be safe for them or not as effective. Vets are governed by the ‘cascade system’, which is a legal framework that means we should always first prescribe medication formulated for the intended species and use, such as the licensed use of Librela for arthritis in dogs.
For those of you whose dogs are already receiving Librela, please be aware we are always monitoring any drug we use in our patients for its effect and safety. Our highly experienced nurses are fantastic at providing great care during the monthly injection appointments and a vet will normally review your pet every 6 months or sooner if we have concerns raised through you or by our nurses.
If your dog has one of the following issues after starting Librela or existing signs that seems to be worsening such as:
- Balance problems
- Trouble standing or walking
- Seizures
- Urinary problems
- Lack of effect in controlling pain
Then, please contact us so our vets can examine your pet and review their management. It’s important to note that most of our patients that receive Librela are our older pets. As such, many more conditions and diseases can cause signs identical to these adverse events. Progressive arthritis may invariably lead to further mobility issues and our arthritic pets can be more prone to the effects of a traumatic injury. By working together, we can identify and treat common conditions that maybe contributing to the above issues, and in the absence of any other cause, alter your pet’s treatment to more suitable medications.
As always, your pet’s health and welfare is paramount to everything that we do at Mayne Veterinary Clinic and the profession at large. We will share any updated information as it’s provided to us. Our vets are always happy to address any concerns you may have. Your pet’s comfort, mobility and safety will always be protected with us.