18 May 2026
American scientists say the technique has shown promise in pilot studies amid hopes it may mean other treatments aren’t needed.
Allister Webb
Job Title
Creative image of embryonic stem cells. Image: pinkeyes / Adobe Stock
New hopes have been raised that stem cell therapy could soon be available to treat cats and dogs with osteoarthritis (OA).
Scientists in California are hoping to secure regulatory approval for mesenchymal stromal cell (MSC) treatments of the disease within the next two years, following pilot research.
But while they have emphasised the need for further analysis, Gallant bosses believe the technique could also work with, or even replace, other current medications.
Rebecca Windsor, Gallant’s vice-president of veterinary affairs, said: “By targeting the systemic and local immune dysregulation that precedes the progressive, degenerative changes of OA, MSC therapy has the potential to not only control clinical signs, but also impact the course of disease.”
The San Diego-based company believes it is already on course to secure regulatory approval for its first stem cell therapy, targeting refractory feline chronic gingivostomatitis, from the US Food and Drug Administration (FDA) later this year.
It now hopes to secure similar backing for OA treatments in 2028 after what it described as significant improvements compared to placebo administration in pilot studies.
Among 88 client-owned dogs enrolled, nearly three-quarters (73.7%) with mild or moderate OA had shown improvements under the Liverpool Osteoarthritis in Dogs (LOAD) assessment model 90 days after treatment.
Meanwhile, in a smaller study of 35 cats, 60% of those treated were found to have a better quality of life under a veterinary assessment three months after treatment, with the proportion rising to 76.2% under owner assessment using a validated tool.
Results from the cat-focused study are said to have been submitted for publication, while longer-term work examining the treatment’s impact over a year remains ongoing.
But the company said it is also in contact with other regulators as well as the FDA about the technique.
Chief executive Linda Black said: “This data marks additional meaningful progress toward a new category of care, where regenerative medicine targets disease at its source.”
A critical question in future development is likely to relate to the extent to which stem cell therapy can be used alongside, or instead of, other treatments.
Dr Windsor acknowledged the need for more OA-related data and said the pilot analyses would support the design of subsequent trials on the path towards FDA approval. But she also indicated that longer-term signs from the development of its feline chronic gingivostomatitis stem cell treatment were promising.
She said: “These cats were dependent on medications for pain and inflammation, and the majority did not need to re-add medications back in in that one year follow-up time.”
Although no figures have been disclosed for the feline research, the company also claimed no serious adverse events were observed in its canine analysis.
Non-serious adverse events were observed in just more than half (53.8%) of the stem cell-treated dogs and nearly 70% of the control animals, though only four cases (6.5%) were considered to be treatment related.