You cannot safely give a cat most human pain medications. Acetaminophen (Tylenol) is potentially lethal to cats even in small amounts, and ibuprofen (Advil, Motrin) is also toxic. The safest thing you can do for a cat in pain is contact your veterinarian, because the medications that actually work for cats are prescription-only. That said, there are several effective options your vet can offer, and understanding them will help you have a better conversation about your cat’s care.
Why Human Pain Medications Are Dangerous for Cats
Cats lack a key liver enzyme (glucuronyl transferase) that humans and dogs use to break down common painkillers. This isn’t a minor difference. It fundamentally changes how these drugs move through a cat’s body.
Acetaminophen is the most dangerous. Because cats can’t process it through the normal detoxification pathway, the drug builds up and produces a toxic byproduct that destroys red blood cells and liver tissue. Cats also have lower levels of the enzyme that repairs damaged hemoglobin, so they develop a life-threatening condition called methemoglobinemia, where their blood can no longer carry oxygen effectively. A single regular-strength Tylenol tablet can kill a cat.
Ibuprofen and other over-the-counter anti-inflammatory drugs are similarly dangerous. They can cause stomach ulcers, kidney failure, and gastrointestinal bleeding. Cats with stomach ulcers often don’t show obvious signs like vomiting blood. Instead, they may become suddenly weak or lethargic as they bleed internally, making the problem hard to catch until it’s severe.
Aspirin has an extremely long half-life in cats compared to other animals, again because of that missing enzyme. Some veterinarians will occasionally prescribe very low doses every 48 to 72 hours for specific conditions, but many won’t prescribe it at all due to the narrow margin between a therapeutic dose and a toxic one.
Prescription Anti-Inflammatory Drugs
The most commonly prescribed anti-inflammatory for cats is robenacoxib, sold under the brand name Onsior. It’s an NSAID designed specifically for feline metabolism. The FDA approved it in 2011 for controlling pain and inflammation after surgery, including spay/neuter procedures and orthopedic operations, in cats at least four months old weighing at least 5.5 pounds. It’s typically limited to three days of use, which makes it better suited for short-term, acute pain rather than ongoing conditions.
Meloxicam is another NSAID sometimes used in cats, though its use tends to be more restricted and carefully monitored due to kidney concerns with longer-term dosing. Your vet will choose between these based on the type of pain, your cat’s age, and kidney function.
Opioid Pain Relief
For moderate to severe pain, especially after surgery or injury, veterinarians often use buprenorphine. It’s an opioid that works well in cats and can be absorbed through the mucous membranes of the mouth, which makes dosing easier. In clinical settings, it’s typically given by injection at around 0.02 mg/kg of body weight. Your vet may send you home with an oral form to give during recovery. It provides reliable pain control but is strictly a short-term medication.
Gabapentin for Nerve and Chronic Pain
Gabapentin has become one of the most widely used pain medications in feline medicine. Originally developed as an anti-seizure drug, it works by interacting with calcium channels in the nervous system to reduce pain signaling. It’s especially useful for nerve-related pain and chronic conditions like arthritis, where inflammation-based painkillers alone aren’t enough.
Veterinarians frequently combine gabapentin with other pain medications. In clinical trials studying cats after spay surgery, gabapentin at roughly 17 mg/kg combined with buprenorphine provided effective pain control. Gabapentin also has a mild sedative effect, which can be helpful for cats that are anxious or restless from pain. Dosing varies widely depending on whether it’s being used for pain, anxiety, or both, so your vet will tailor it to your cat’s situation.
Monthly Injections for Arthritis Pain
One of the biggest advances in feline pain management is frunevetmab, sold as Solensia. It’s a monthly injection your vet administers that targets nerve growth factor, a protein involved in pain signaling. By neutralizing this protein, the drug reduces the sensitization that makes arthritic joints increasingly painful over time.
In a large clinical trial, about 76% of cats treated with frunevetmab showed meaningful improvement in pain and mobility by day 56, compared to roughly 65% of cats on placebo. The separation between treatment and placebo grew stronger when researchers looked at cats with the greatest improvements: among cats that achieved at least a 50% reduction in disability scores, frunevetmab significantly outperformed placebo. Veterinarian-assessed joint pain scores dropped by about 50% over the course of treatment.
Solensia is particularly valuable because it avoids the kidney and stomach risks associated with long-term NSAID use. For older cats with chronic arthritis, who often also have some degree of kidney disease, it fills a gap that previously left many cats without good options.
Supplements and CBD
Glucosamine and chondroitin supplements are widely marketed for joint health in cats. Products like Dasuquin (which contains 125 mg glucosamine, 100 mg chondroitin sulfate, and avocado/soybean extracts per capsule) are popular, but the clinical evidence is disappointing. Studies in cats have consistently failed to show that glucosamine/chondroitin supplements reduce pain compared to placebo. In one head-to-head comparison, cats on meloxicam showed significant improvement in mobility and pain scores while cats on glucosamine/chondroitin did not. These supplements are unlikely to cause harm, but they shouldn’t be relied on as a primary pain treatment.
CBD products are a newer area of interest. A small study of 26 cats with osteoarthritis pain found that a CBD/CBDA paste significantly reduced pain scores after six weeks. However, nearly half the cats dropped out of the study, mostly because they refused to eat the paste or vomited after taking it. The results are encouraging but preliminary, and CBD products for pets aren’t regulated the same way pharmaceuticals are, so quality and dosing vary widely between brands.
How to Tell if Your Cat Is in Pain
Cats are notoriously good at hiding pain, which is why many owners don’t realize their cat is suffering until the problem is advanced. Veterinary researchers developed the Feline Grimace Scale, a facial expression-based system that can help identify acute pain. The key things to watch for are squinted eyes, ears flattened or rotated outward, a tense muzzle, and whiskers that are bunched forward or pressed against the face.
Beyond facial expressions, painful cats often show changes in behavior: hiding more than usual, losing interest in food, reluctance to jump onto surfaces they used to reach easily, aggression when touched in certain areas, or a hunched posture. Cats with arthritis may stop grooming their lower back and hind legs, leading to a matted or unkempt coat in those areas. Any of these signs warrants a veterinary visit, because identifying the source of pain determines which treatment will actually help.