Stem-cell therapy shows promise for horse soft-tissue injury, disease

Stem-cell therapy shows promise for horse soft-tissue injury, disease

May 01, 2008

Before and after: A torn inferior check ligament is traced between November 2007 (left) and eight weeks later in January 2008 to show improvement after treatment with adipose-derived stem cells.
While interest and controversy swirl around stem-cell use for treating human spinal-chord injuries and diseases ranging from diabetes to Parkinson's, veterinary medicine has been investigating stem-cell use for a variety of animal conditions and diseases.

One intriguing possibility is stem-cell therapy for soft-tissue (tendon and ligament) injury and joint disease in horses and dogs.

"Stem cells hold tremendous promise for the treatment of tendonitis and joint repair," says Lisa Fortier, DVM, PhD, Dipl. ACVS, associate professor of large-animal surgery at Cornell University's School of Veterinary Medicine.

Others agree, including Jose Garcia-Lopez, VMD, DMS, Dipl. ACVS, who has been using stem-cell therapy to treat soft-tissue injuries for about two and a half years at the Cummings School of Veterinary Medicine at Tufts University in North Grafton, Mass.

Also familiar with the therapy is Wes Sutter, DVM, Dipl. ACVS, at Ocala Equine Hospital in Ocala, Fla.

"For about seven years I've been treating tendon and ligament injuries with platelet-rich plasma (PRP). From a clinical standpoint the results have been encouraging. However, horses with significant scarring or chronic injuries do not appear to respond as well as do the acute anechoic lesions," Sutter says.

"Basically the big change that I've made in the past year and a half is that I'm adding stem cells to the PRP. This provides sort of the healing trinity — a provisional matrix from the fibrin in the PRP, growth-factor release from the activated platelets and progenitor or trophic cells to support quality fibroplasia and hopefully remodeling of the abnormal tissue."

Stem cells are undifferentiated cells capable of self-renewal through replication and differentiation into specific cell lineages. There are two broad categories of stem cells — embryonic and adult-derived.

Embryonic (ES) cells formerly were derived from Day-8, pre-implanted blasto-cysts. Recently, however, scientists have learned how to insert key genes into adult cells, effectively "turning" them into embryonic stem cells. No embryo is generated or destroyed, thereby avoiding the previous ethical controversy over embryonic stem cells. Significant scientific hurdles remain, though, before these cells can be used clinically.

Adult-derived mesenchymal stem cells (MSC) can be obtained from a variety of tissues, including bone marrow, adipose tissue, muscle, cartilage, trabecular bone and tendon. And there are hematopoetic stem cells (HSC) derived from bone marrow, capable of forming all types of blood cells.

The interest in stem cells centers on their potential to differentiate into a variety of cell types, including those of tendons and joints.

The challenge for veterinary medicine is determining which stem-cell types are best suited and most valuable to treat horse injuries and disease.