A shot every three months helps cats move better, a win for arthritis in pets

If your older cat has stopped leaping onto the couch, there is good news for arthritis in pets. A new shot, given just once every three months, helped most cats with arthritis feel and move better in a large trial.

The shot is called relfovetmab. Owners saw real improvement in their cats’ daily activities, and some saw it within days. For a cat that hates car rides and carriers, four shots a year is a lot easier than a daily pill.

How the study worked

Researchers followed 307 pet cats with arthritis, with a median age of 11.0 years, at several veterinary clinics. By chance, half got relfovetmab and half got a saltwater placebo, as an injection under the skin every three months for three doses. Neither the owners nor the vets knew which cat got which. The trial ran nine months and was published Oct. 2, 2026, in The Veterinary Journal. Owners did most of the judging, since they know best how their own cat behaves at home.

What they found

Success meant that owners saw a clear improvement in the activities that were hardest for their cat. At day 90, that happened for 73.0% of cats who got relfovetmab. For cats who got the placebo, it was 46.8%. That means most treated cats got better, and clearly more of them than with the fake shot.

The benefit showed up early, as soon as three days after the first dose. It held through the whole nine months. Owners also rated their cats higher on quality of life, temperament and happiness, and the vets’ own pain checks pointed the same way.

Safety looked good too. Side effects of any kind were about as common in both groups: 44.4% with relfovetmab and 39.6% with placebo. The one difference was pain at the injection spot, which happened in 7.2% of treated cats and 1.3% of placebo cats. A cat’s body made antibodies against the drug in only 3 cats (1.97%). It was temporary and did not affect safety.

Why cats hide arthritis

Arthritis is very common in older cats, but it often goes unnoticed. Cats hide pain. The signs are easy to mistake for normal aging: jumping less, sleeping more, skipping grooming, or seeming grumpy when touched.

The shot works differently from many pain medicines. It is an antibody, a protein made to block nerve growth factor. That is one of the body’s pain signals. Blocking it turns down the pain at its source.

What you can do today

Take five minutes and watch your older cat jump. Encourage it to hop onto a couch or chair a few times, and notice whether it hesitates, jumps shorter or skips it. Jot down what you see, along with any changes in grooming, sleep or litter box habits. That note is exactly what your vet needs to check for arthritis and talk about pain treatment.