If your cat receives Solensia for arthritis pain, there is new safety information to review with your veterinarian.
On October 5, 2026, the FDA approved safety-related changes to Solensia’s labeling. These changes include more information about reported side effects and a new information sheet for cat owners. Your veterinarian should provide and discuss this sheet before every injection, even if your cat has received Solensia before.
Read the update here: FDA Animal Drug Safety-Related Labeling Changes—Solensia.
What does Solensia do?
Solensia, also called frunevetmab, is a monthly injection for arthritis pain in cats. It blocks a protein called nerve growth factor, or NGF, which helps send pain signals to the brain.
Solensia may reduce pain, but it does not repair a damaged joint or slow or reverse arthritis. A cat that moves more easily may still have joint disease. That difference matters when we judge how well the treatment is working.
What safety problems have been reported?
The updated label includes reports of:
- Severe itching, scabs, sores, and hair loss
- Poor appetite, low energy, weight loss, and anemia
- Vomiting, diarrhea, and inflammation of the pancreas
- Poor balance, seizures, weakness, and paralysis
- Limping, swollen joints, trouble jumping, and changes in walking
- Hiding, unusual behavior, and increased crying
- Increased thirst or urination and changes in kidney blood tests
- Severe allergic reactions
Some reports involved death or euthanasia.
These reports deserve attention. However, a problem reported after an injection does not, by itself, prove that Solensia caused it. The FDA explains that these reports cannot reliably tell us how often a problem happens or establish its cause.
My concerns go beyond pain relief
As a veterinarian who focuses on mobility and joint health, I want to know more than whether a cat seems less painful. I also want to know whether the joints, muscles, and nervous system remain healthy.
One of my concerns is rapid joint damage in some cats treated with Solensia. Rapidly progressive osteoarthritis, or RPOA, means joint damage that worsens much faster than expected. I am also concerned about unusual bone loss and changes in joint shape or stability.
The FDA update lists joint swelling, lameness, weakness, and walking changes. It does not establish that Solensia causes RPOA or destructive joint disease. These remain concerns that need careful study. We should take them seriously while being clear about what we do and do not know.
I am also concerned when weakness or poor balance is treated as arthritis without checking for other causes. A cat with trouble walking may need an examination of both its joints and nervous system.
Start with a clear picture, and keep checking
Before treatment, I recommend a careful examination and, when appropriate, X-rays of the affected joints. This helps confirm the diagnosis and gives us a starting point for future comparisons.
The veterinarian should check for pain, swelling, muscle loss, and differences between the two sides of the body. Owners can help by taking short videos of their cat walking, jumping, and using stairs.
Repeat these checks during treatment. Watch for new limping, swollen joints, reduced jumping, weakness, or a change in how your cat stands. Owners can also ask their veterinarian how to gently check for swelling or differences between limbs at home.
Improvement in pain should not replace regular checks of joint health.
What should veterinarians do?
The updated FDA labeling gives veterinarians clear steps to follow:
- Provide and review the Client Information Sheet before every injection. This applies to new patients and cats already receiving Solensia. Discuss possible side effects and answer the owner’s questions.
- Explain that serious reactions can occur. Owners should understand that reported problems include severe itching, weakness, trouble walking or jumping, seizures, and other signs of illness. Some reported cases ended in death or euthanasia.
- Review the cat’s health and response before continuing. Ask whether treatment is helping and whether there are new symptoms. Discuss skin, balance, seizure, kidney, or pancreatic problems, previous allergic reactions, and all medicines and supplements. Review any previous or current treatment with other monoclonal antibodies, which are medicines made from special proteins.
- Evaluate new health problems before giving another dose. The new owner information sheet says cats with new problems or recent health changes should not receive Solensia because further testing may be needed before starting or continuing treatment.
- Tell owners what to watch for and when to call. Encourage them to report changes promptly, including poor appetite, vomiting, diarrhea, increased thirst or urination, unusual behavior, or changes in movement.
In my practice, I would also document this discussion, track the cat’s mobility and joint health, and report suspected side effects. Baseline X-rays, repeat joint examinations, and home videos are additional recommendations I support. They are not specific requirements of this FDA labeling update.
Each injection should be a fresh decision
Before the next dose, tell your veterinarian about any health changes and all medicines or supplements your cat receives. Discuss whether Solensia is helping and whether further testing is needed.
A monthly injection visit should include a fresh review of the cat’s health, comfort, and movement. Continuing treatment should depend on that review.
Contact your veterinarian promptly if your cat develops concerning signs. Collapse, trouble breathing, seizures, or sudden inability to stand need urgent veterinary care.
Suspected side effects can be reported to Zoetis at 1-888-963-8471 or through the FDA’s animal drug reporting page.
Cats deserve relief from arthritis pain. They also deserve careful monitoring, clear discussions about risk, and a treatment plan that changes when their health changes.
Leave a Reply