Regenerative medicine has offered new treatment options for veterinarians managing osteoarthritis in horses. Almudena Pradera-Munoz, DVM, PhD, chief scientific officer at EquiCord, in Madrid, Spain, presented a summary of information from her doctoral thesis paper, and the work of other researchers, on the use of one such option—umbilical-cord-derived mesenchymal stem cells (MSCs)—for treating equine osteoarthritis at the Equine Regenerative Medicine and Orthobiologics Summit, held Oct. 3-25, 2022.

“Every time a horse makes some effort, there are very, very small traumas in the synovial (joint) capsule,” said Pradera-Munoz. This eventually creates an inflammatory environment within the joint, that subchondral bone (the layer lying directly beneath the cartilage) responds to by making new bone, beginning the cycle of osteoarthritis. She reminded veterinarians they must administer anti-inflammatory therapy frequently, because the inflammatory processes occur constantly within the joint.

Mesenchymal stem cells (MSCs) are self-renewing stromal cells that can be isolated from several sources, including the umbilical cord, fat, and bone marrow. Pradera-Munoz said researchers have shown the key advantages of using umbilical-cord-derived MSCs over other sources in regenerative joint therapy are:

• Greater capacity for proliferation: This allows them to expand more efficiently during the manufacturing process.
• More genetic stability: Umbilical-cord-derived MSCs are less likely to have chromosomal abnormalities or mutations that could pose safety problems in the recipient horse.
• Less risk of accidental virus transmission: MSCs are collected at the time of birth, so they are less likely to be contaminated with pathogens such as viruses and, bacteria.
• Improved animal welfare: Collecting umbilical-cord-derived MSCs is a noninvasive process.

Mesenchymal stem cells’ mechanism of action does not lie in the cells themselves, said Pradera-Munoz, but rather in their ability to immunomodulate and stimulate healing in the cells of the animals into which they’re injected.

“The take-home message is to treat the horse as early as possible because if treated very early, there are clear signs of synovial regeneration,” said Pradera-Munoz. “In cases where synovial cartilage is at least 50% destroyed, it is impossible to regenerate tissue, but the horse might show signs of recovery, such as improvement in lameness, pain, and overall quality of life.”