When Bandito, a 12-year-old chihuahua, began to suffer from the effects of arthritis, Bandida did what most responsible dog owners do and took their dog to the vet. The vet recommended a monthly shot of Librela, an arthritis shot Bandida was told had no side effects.
Shortly after Bandito’s second shot, he fell ill and died in extreme pain from kidney failure caused by hypercalcemia.
In another part of the world, Debbie was making a very similar decision. Her 13-year-old chihuahua, Abigail, started favoring her back leg when walking around. Debbie took her pup to the vet a few times for the pain and was eventually recommended Librela.
Everything seemed to be going well for her pup, who showed great improvements in her arthritis two days after the shot. Unfortunately, just 5 days later she had to be euthanized after abruptly developing ataxia.
Both dogs were seniors, and senior dogs do tend to develop health complaints as they get older—but the number of similar cases is enough to raise anyone’s eyebrows. The FDA issued a letter to Veterinarians warning them about potential side effects after they received over 3,600 similar complaints. 80% of those complaints were from the veterinarians serving those pets.
Outside the US, The European Database of Suspected Adverse Drug Reaction Reports lists over 30,000 animals with adverse reactions.
A Facebook group on Librela side effects with over 35,000 members suggest that there may be many more dogs suffering than those whose owners formally reported symptoms.
Side Effects to Know About
Librela has been on the market a very short amount of time. It was approved for medical use in the UK in 2020, and in the USA in 2023. During that time, over 21 million doses of Librela have been given.
This means that although there have been thousands of formal complaints, the symptoms are still classified as “rare.” For the dogs unlucky enough to have an adverse reaction, these symptoms include:
- Ataxia
- Convulsion
- Paresis
- Proprioception abnormality
- Paralysis
- Recumbency
- Muscle weakness
- Muscle tremors
- Lameness
- Collapse NOS (Not otherwise specified)
- Immune-mediated PTs (IMHA, IMTP, IMPA)
- Pancreatitis
- Death
(List from the FDA Website, available for download here.)
Many veterinarians are currently performing independent studies on Librela right now. Dr. Mike Farrell for example, is an orthopedic specialist with dozens of scientific papers written on canine joint health. He has written joint related chapters in veterinary textbooks, and is a board-certified veterinary surgeon.
He has worked with many other experienced veterinarians, in one paper for a combined 128 years of experience in the field. Their work suggests that Librela may be detrimental to joint health rather than helpful.
Librela is an anti-nerve-growth factor monoclonal antibody. The treatment was first tested for human use, but ultimately rejected because it caused arthritis to get even worse after treatment. A study done on Librela indicated that although it worked in healthy beagles with 6 months of treatment, boney changes couldn’t be ruled out.
Farther testing in rabbit models shows that it can, in fact, cause osteoarthritis to worsen outside of humans.
Not a Perfect Cure
On top of these side effects, the promised reward of a pain free dog may not be all that is promised. In November of 2023, the FDA warned manufacturer Zoetis that the Librela website contained misleading or false information.
They again received a second letter about misleading information on their Youtube channel February of 2025 due to showcasing improvements in a dog visually but making the side effects hard to access.
This isn’t an uncommon thing in the vet medicine industry, but it does illustrate the concerns many pet owners have. If they had gotten a clear look at the side effects, would they have chosen to go forward with treatment?
Risk Vs. Reward
Despite thousands of dogs suffering severe side effects from Librela, many more dogs are living improved lives. The issue most owners are angered over isn’t the side effects—it’s that their vet told them that there weren’t any.
Owners want better disclosure when their vet brings up Librela. The drug still benefits millions of dogs, who otherwise might suffer through their end years. They would like their vets to mention the side effects, let them know what the risk level is, and have a strategy for if those side effects happen.
This way, owners aren’t caught by surprise if their dog has a side effect, and they have a plan in place if it occurs.
Librela Responds
In February, Librela responded to the FDA letter by updating their labeling. The labeling now reports the side effects the FDA noted and offers a phone number to report adverse drug reactions to. You can read the updated prescription labeling here.
If your dog has suffered side effects from Librela, reporting it to the manufacturer is one of the best things you can do. You can report an adverse side effect by calling 1-888‑963-8471.
Per the FDA website, when reporting adverse events to the FDA and/or Zoetis, please include if available:
- A full medical history
- How many times the dog has received Librela
- Lot number of vial used
Alternatives to Librela
If you find the potential side effects of Librela too risky, the good news is that there are other treatment options for arthritis available. When our dog Rocco was suffering from arthritis, cold laser therapy ended up working miraculously with no side effects. You can read our story here.
Rocco’s success with cold laser was nothing short of transformative, but there are other options available as well. These include:
- Supplements such as glucosamine, turmeric, green lipped mussels
- Aquatherapy
- Appropriate pain medicine
- Physical therapy
Every dog is different. My dogs would rather die than do aquatherapy, but some dogs may love it. My dog responded very well to cold laser therapy, but it might not be available or the right choice for another dog.
In the end, you have to be your pet’s advocate. Speak with your vet, including asking them to read the labeling on any medicines or treatments to make sure you are alerted to potential side effects. Knowledge is half the battle, and understanding potential side effects can help you spot and treat them early should they come up.
Similar Posts:
- Cold Laser Therapy for Dogs
- Green Lipped Mussel Joint Supplement
- Vet Billing – A Potential Solution to High Vet Bills
- Why Is My Chihuahua Shaking?
- Our Experience With In-Home Euthanasia
WOW!!! I hadn’t heard about Librela’s side effects. It seems too risky to try. I currently give Henry a supplement for joint health. It does help. I won’t go along with any vet suggesting Librela now. Excellent and extremely valuable article, Andrea! Thank you! I’m sharing it with all my dog parents.
I think it might be useful in certain circumstances, for example, if it is a terminally ill dog and this is a last ditch effort, even if they end up with side effects the potential reward outweighs the risk. I’m a little horrified however, that they didn’t admit to these risks at all at first. I hope it was unintentional.
Wow, this is every pet parent’s worst nightmare. Trust the vet and your dog might end up dead? This is truly terrible to hear. I would not touch the stuff after reading your post. If many people are discovering dreadful side effects then this needs to be withdrawn (even if it is doing some good to a few!!)
Your suggestions for alternatives are gold dust. There are several I would be happy to consider instead. Thank you.
I’ve heard both horror and success stories about Librela. It was brought up as an option for our husky but we decided to do stem cell surgery instead. So glad we did! She has improved soooo much and no side effects!!
I have been following the Liberla story for months now, reading the sad stories of dogs passing, the side effects and so much more, it is one medication I would not give to Nili as I would not take the chance, it is time they took it off the market and I have seen petitions calling for that to happen. The company in my opinion has no respect for dogs and that is very sad. Great article and eye opener for those that do not know.
I confess, I probably wouldn’t use it either. Cold laser therapy worked so well for Rocco’s arthritis, it will likely be my go to if any of my other dogs end up in pain. Our supplements seem to be working well though because no signs of soreness at 12, 13 and 14 years old.
Very informative post. The numbers coming out now are frightening! I gave my Huskies supplements and Cold Laser Therapy when needed, and very glad I did! When they came out with Trifexis for ticks and fleas, it, too, was touted as being a great choice, until many dogs began getting very ill, and my one Husky went temporarily blind, and my vet took it off his shelf. It’s promising, but scary, when new things come out. As a rule, I wait until something has been around for a long while. I feel so bad for all the dogs and their families that were harmed by Librela.