An oral hyaluronan product did not produce any improvement in clinical or biochemical parameters in horses diagnosed with osteochondrosis in a new study, researchers from the Universidad de Caldas, in Columbia, recently reported. The study authors concluded that the evaluated product likely resulted in no detectable effect due to the small number of horses included in the study; however, they did state the treatment "did not produce any adverse clinical effects and was well tolerated by the horses in the study."
Osteochondrosis is a developmental orthopedic disease characterized by swelling and pain in the affected joints. It's caused by failed ossification (bone formation), which occurs most frequently in the hock, stifle, and fetlock joints.
"It is now well established that arthroscopic treatment, the surgical removal of osteochondral fragments, the debridement of the affected joint surface, and articular lavage are the most appropriate treatments for this disease," the researchers noted. "In many cases, early arthroscopic surgery can stop the development of the disease and prevent it from progressing to osteoarthritis."
But for horses not treated arthroscopically, or who continue to show clinical signs of disease postoperatively, alternative treatments are needed.
One such possibility is oral administration of hyaluronic acid. Previous studies have demonstrated hyaluronic acid's ability to alter cartilage metabolism when injected into a joint. But research into the effectiveness of its oral formulation is limited.
To evaluate the effect of oral hyaluronic acid in horses with osteochondrosis of one tarsocrural (hock) joint, researchers randomly separated 11 horses to either a treatment or control group. They administered 250 mg of a commercial oral hyaluronan product (trade name Hyal-Joint) or a placebo orally once daily for 60 days. The researchers assessed various clinical and biochemical parameters at the end of 60 days of treatment and again 30 days after cessation of supplementation.
Key findings of the study were:
- No significant improvement in lameness scores;
- No significant change in concentration of various inflammatory mediator levels (e.g., nitric oxide, prostaglandin E2);
- No significant change in synovial effusion, and
- No significant difference in hyaluronic acid concentrations in either blood or synovial fluid.