Solensia for Cats: The Monthly Arthritis Injection That Changes Everything

Last updated: March 26, 2026

For decades, there was no safe, long-term pharmaceutical option approved specifically for feline arthritis pain. Dogs had a growing list of FDA-approved pain medications, but cats — with their uniquely sensitive metabolisms — were largely left out. Solensia for cats changed that equation entirely, offering the first biologic treatment built from the ground up for feline pain relief. This guide covers everything you need to know, from the science behind it to whether your cat might be a candidate.

What Is Solensia (Frunevetmab)?

Solensia is the brand name for frunevetmab, a monoclonal antibody therapy manufactured by Zoetis specifically for the control of pain associated with osteoarthritis in cats. Unlike traditional painkillers that work by blocking enzymes or altering neurotransmitter activity across the entire body, Solensia is a biologic — a lab-engineered antibody that targets one very specific protein involved in the pain signaling pathway. The active ingredient, frunevetmab, is a felinized monoclonal antibody, meaning it has been designed to closely resemble a cat’s own natural antibodies. This is an important distinction because it means the cat’s immune system is far less likely to recognize the drug as foreign and mount a reaction against it.

Solensia is administered as a subcutaneous injection — a small shot given just under the skin — once per month at your veterinarian’s office. It is not a pill, a liquid, or a transdermal medication, which eliminates the daily struggle of medicating a reluctant cat. For many owners, this alone is a significant advantage, since cats are notoriously difficult to medicate at home.

How Solensia Works: The Anti-NGF Antibody Approach

To understand why Solensia for cats represents a genuine departure from older pain management strategies, it helps to understand the molecule it targets: nerve growth factor, or NGF.

NGF is a protein that plays a central role in the development and maintenance of nerve cells. Under normal conditions, NGF helps nerves grow, survive, and function. However, in osteoarthritis, damaged and inflamed joint tissues produce dramatically elevated levels of NGF. This excess NGF binds to pain receptors on sensory nerve endings in and around the joint, amplifying pain signals sent to the brain. The result is chronic, escalating discomfort — the kind that makes a cat reluctant to jump onto a favorite chair, slow to climb stairs, or unwilling to play.

Frunevetmab works by binding to NGF before it can reach those pain receptors. The antibody circulates in the bloodstream, intercepts free-floating NGF molecules, and neutralizes them. With less NGF available to stimulate pain pathways, the cat’s nervous system receives fewer pain signals from the arthritic joints. The joint damage itself is not reversed — osteoarthritis remains a structural disease — but the cat’s perception of pain is significantly reduced, allowing improved mobility and quality of life.

This mechanism is fundamentally different from NSAIDs, which block COX enzymes involved in inflammation, or gabapentin, which modulates nerve signaling broadly. By targeting a single upstream pain mediator, Solensia avoids many of the systemic side effects that limit the long-term use of those older drug classes in cats.

FDA Approval: A Historic First for Feline Pain Management

Solensia received FDA approval in January 2022, making it the first monoclonal antibody therapy approved for pain control in any animal species in the United States — and the first FDA-approved treatment specifically indicated for osteoarthritis pain in cats. The approval was based on a pivotal field study showing statistically significant improvements in owner-assessed pain and mobility scores compared to placebo, with a favorable safety profile throughout the treatment period.

Prior to Solensia’s approval, veterinarians managing feline arthritis pain were limited to off-label use of drugs designed for other species or conditions. The arrival of an on-label, cat-specific treatment represented a genuine milestone in feline medicine.

Which Cats Is Solensia For?

Solensia is indicated for cats diagnosed with osteoarthritis — a degenerative joint disease that is far more common in cats than most owners realize. Studies suggest that over 60 percent of cats aged six and older have radiographic evidence of osteoarthritis, and by age 12, that number may exceed 90 percent. Cats are masters at hiding pain, so the condition is dramatically underdiagnosed.

Signs that a cat may be living with arthritis pain include reluctance to jump up or down, difficulty using stairs, stiffness after resting, reduced grooming (especially along the back or hind legs), avoiding the litter box or missing the sides, decreased playfulness, irritability when touched in certain areas, and a general withdrawal from activities they once enjoyed. If your cat is showing any of these signs, a veterinary evaluation is warranted.

Solensia is approved for use in cats weighing at least 5.5 pounds (2.5 kilograms) and at least seven months of age. It is used in cats of all breeds and sizes. If you are considering adopting a senior cat, knowing that effective arthritis management now exists may help ease concerns about caring for an older feline companion.

How Solensia Is Given: The Monthly Injection Process

Solensia is administered exclusively by a veterinarian or licensed veterinary technician — it is not available for at-home use. The injection is subcutaneous, delivered just under the skin in the scruff area between the shoulder blades. Most cats tolerate it extremely well, and the process takes only a few seconds.

The dose is weight-based, recalculated at each monthly visit. Consistency matters — maintaining a regular monthly schedule keeps circulating antibody levels steady and prevents gaps in pain control. Missing a dose can allow pain to return, and some owners report needing an additional cycle or two to regain the same relief after a lapse. Each monthly visit also gives your veterinarian a built-in opportunity to assess overall health and track progress.

How Fast Does Solensia Work?

Many cat owners notice improvements within the first week after the initial injection — cats jumping onto counters they had been avoiding, resuming play behavior, or grooming more thoroughly. However, the response timeline varies. Some cats require two or even three monthly injections before the full benefit becomes apparent.

Veterinarians generally recommend committing to at least three consecutive monthly injections before evaluating whether Solensia is effective for a particular cat. Because osteoarthritis is a chronic condition, Solensia is intended for ongoing use rather than as a short-term intervention.

Side Effects of Solensia for Cats

In clinical trials, Solensia demonstrated a favorable safety profile. The most commonly reported side effects were mild and self-limiting: injection site reactions such as temporary swelling or tenderness, vomiting, diarrhea, and mild lethargy in the first day or two following injection.

Allergic or hypersensitivity reactions are possible but were uncommon in clinical studies. Signs include facial swelling, hives, difficulty breathing, or collapse — contact your veterinarian immediately if any of these occur. Some cats may develop anti-drug antibodies over time, which could reduce effectiveness; your veterinarian will monitor for any decline in response.

Importantly, Solensia does not carry the gastrointestinal, kidney, or liver toxicity risks associated with NSAIDs — one of its most significant clinical advantages and a major reason it has been so widely adopted for feline patients.

How Much Does Solensia Cost Per Injection?

The cost of Solensia varies by veterinary practice, geographic region, and the weight of the cat. Most cat owners can expect to pay between $50 and $130 per monthly injection. Some practices charge an additional examination fee, while others bundle the exam into the injection cost for cats on a regular schedule. Over a year, this translates to roughly $600 to $1,500 in medication costs — a meaningful expense, though many owners find it comparable to the combined costs of multiple oral medications, supplements, and the monitoring visits those drugs require.

Pet insurance policies increasingly cover Solensia as a prescribed treatment for a diagnosed condition. Check with your provider about coverage for biologic therapies if your cat has insurance.

Solensia vs NSAIDs vs Gabapentin for Cat Arthritis

NSAIDs (meloxicam, robenacoxib): Cats metabolize NSAIDs slowly, and long-term use carries significant risks of gastrointestinal ulceration, kidney damage, and liver toxicity. Neither meloxicam nor robenacoxib (Onsior) is FDA-approved for long-term feline use in the United States. The need for careful dose monitoring and periodic bloodwork makes long-term NSAID therapy in cats a calculated bet.

Gabapentin: Used off-label for feline pain, gabapentin can help with neuropathic discomfort but is not anti-inflammatory, and its most prominent side effect — sedation — can significantly affect quality of life. It also requires daily oral administration, which is a persistent challenge with cats.

Solensia (frunevetmab): Targets pain at the source via anti-NGF activity. Given once monthly by injection — no pills, no daily dosing. Does not carry the kidney, liver, or GI risks of NSAIDs. Does not cause sedation. FDA-approved specifically for feline OA pain. The primary trade-offs are cost and the requirement for monthly veterinary visits.

Some veterinarians use Solensia as standalone treatment, while others combine it with gabapentin, joint supplements, laser therapy, or physical rehabilitation for a multimodal approach. The right combination depends on the individual cat.

Long-Term Safety Data

The pivotal clinical trial supporting Solensia’s 2022 approval ran for approximately three months. Since then, post-market surveillance and real-world use have continued to accumulate data. To date, the long-term safety profile has remained consistent with clinical trial findings — no new or unexpected safety signals have emerged, and veterinarians report that most cats tolerate it well over sustained treatment periods spanning a year or more.

Because NGF plays roles beyond pain signaling — including wound healing and nerve maintenance — there has been theoretical interest in whether long-term blockade might impair these processes. Clinical experience has not revealed significant issues, but it remains an active area of observation. Zoetis and independent researchers continue studying extended treatment periods, and updated safety information is incorporated into prescribing guidelines as it becomes available.

Candidacy: Why Solensia Is Kidney Safe

One of the most clinically important features of Solensia for cats is its safety in patients with compromised kidney function. Chronic kidney disease (CKD) is extremely common in older cats — the same population most likely to suffer from osteoarthritis. In the past, veterinarians were often forced to choose between managing arthritis pain and protecting fragile kidneys, because NSAIDs posed a direct threat to renal function.

Solensia does not rely on kidney or liver metabolism for clearance. As a monoclonal antibody, it is broken down through normal protein catabolism — the same process the body uses to recycle its own antibodies. This means it does not place additional burden on the kidneys or liver, making it viable for cats with mild, moderate, or even advanced kidney disease. This kidney-safe profile has been one of the primary drivers of Solensia’s rapid adoption. If your cat has been diagnosed with both CKD and osteoarthritis, ask your veterinarian whether Solensia is appropriate. Cats with other chronic conditions — hyperthyroidism, diabetes, heart disease — should be evaluated on a case-by-case basis.

Monitoring Your Cat on Solensia

Most veterinarians recommend baseline bloodwork — a complete blood count and chemistry panel — before starting Solensia, particularly in older cats or those with known health conditions. Periodic rechecks every six to twelve months help monitor kidney function, liver values, and overall metabolic health. The monthly injection visits themselves provide built-in professional oversight at every dose.

At home, keep a simple log of your cat’s behavior and mobility — jumping confidence, play frequency, grooming habits, and stiffness after rest. These observations are invaluable to your veterinarian in assessing whether the treatment is working. Report any new symptoms promptly so your veterinary team can determine whether they are related to Solensia or another issue.

Success Stories: What Owners Report

The most consistent theme in owner reports about Solensia for cats is the return of behaviors that had quietly disappeared. Cats that had stopped jumping onto beds begin leaping up again. Cats that had abandoned their favorite perch return to it. Cats that had become irritable and reclusive start seeking affection again. Veterinarians report similar observations — cats that were stiff and reluctant to move during examinations show dramatically improved range of motion after a few months of treatment. Some cats considered candidates for end-of-life discussions due to immobility were given a meaningful extension of comfortable, active life.

Not every cat responds equally, but the response rate in practice has been high enough to make Solensia one of the most rapidly adopted veterinary products in recent memory. If you are caring for a senior cat with declining mobility, a conversation with your veterinarian about Solensia is well worth having. If you are considering adopting an older cat, know that treatments like Solensia mean senior cats can live comfortably for years after diagnosis. Explore our cat breeds directory to learn more about breeds that may be predisposed to joint issues as they age.

Frequently Asked Questions

Can Solensia be given at home instead of at the vet?

No. Solensia is currently approved for administration by a veterinarian or licensed veterinary professional only. It is not available for at-home use. The monthly veterinary visit requirement ensures proper dosing, allows for monitoring, and provides an opportunity for your veterinarian to assess your cat’s overall health and treatment response at every administration.

How long does a cat need to stay on Solensia?

Because osteoarthritis is a chronic, progressive condition, Solensia is intended for long-term ongoing use. There is no set endpoint for treatment. Cats typically continue receiving monthly injections as long as they are benefiting from the medication and tolerating it well. If treatment is stopped, the pain-relieving effects will wear off as circulating antibody levels decline, and arthritis discomfort will return. Your veterinarian can help you decide on the best long-term plan for your cat.

Is Solensia safe for cats with kidney disease?

Yes. Solensia does not rely on kidney or liver metabolism for elimination, making it one of the safest pharmaceutical pain management options for cats with chronic kidney disease. This is a major clinical advantage over NSAIDs, which can worsen kidney function. Your veterinarian will still want to monitor your cat’s kidney values periodically, but the medication itself does not impose additional renal burden.

Can Solensia be used together with other pain medications?

In many cases, yes. Veterinarians sometimes use Solensia alongside gabapentin, joint supplements, omega-3 fatty acids, or non-pharmaceutical therapies such as laser treatment, acupuncture, or physical rehabilitation. The decision to combine therapies depends on the severity of your cat’s arthritis, their response to Solensia alone, and any other health conditions they may have. Always consult your veterinarian before adding or changing any medications.

What if my cat does not respond to Solensia?

Not all cats respond to the same degree. Veterinarians recommend at least three consecutive monthly injections before concluding that Solensia is not effective for a particular cat. If your cat has not shown improvement after three doses, your veterinarian may reassess the diagnosis — ensuring that the pain is indeed from osteoarthritis and not another condition — and discuss alternative or complementary treatment strategies. Some cats benefit from combining Solensia with other modalities even if the antibody alone provides only partial relief.

Does Solensia cure arthritis in cats?

No. Solensia manages the pain associated with osteoarthritis but does not reverse or cure the underlying joint damage. Osteoarthritis involves permanent structural changes to the cartilage, bone, and surrounding tissues of the joint. What Solensia does is significantly reduce the pain signals generated by that damage, allowing the cat to move more comfortably and maintain a better quality of life despite the disease. Weight management, environmental modifications, and physical therapy can complement Solensia by reducing mechanical stress on affected joints.