Use of Hyaluronic Acid in Performance Horses

The use of hyaluronic acid in the maintenance of joint health is well established in the scientific literature. Trouble-free joint function hinges on two substances, hyaluronic acid and water.

Oral absorption of Hyaluronic Acid

  • 99M technetium radiolabeled studies in wistar rats and beagle dogs has established
    • 3% of the oral dose is absorbed and taken up in joints and connective tissue
    • Scintigraph scans of the dog and rat show uptake of hyaluronic acid in the joints
  • A study by Scott Pierce, DVM evaluating intravenous and oral administration of hyaluronic acid (100 mg of hyaluronic acid orally daily – single 40 mg intravenous dose) compared to control demonstrated
    • Oral group was the only group to have substantial increase in serum hyaluronic acid on day 7

Comparison of Oral Dosage of Mobility HCC with Intravenous Dose

  • Recommended dose of intravenous hyaluronic acid 2 ml (small joints) and 4 ml (large joints) once or twice weekly for 4 weeks (maximum 8 injections of 10 mg hyaluronic acid/ml equals 80 mg – 160 mg per treatment cycle)
  • Recommended administration of Mobility HCC 30 ml daily for 33 days (equals 24,750 mg of hyaluronic acid)
  • Based on 13.3% uptake into joints and connective tissue, there is approximately 3,290 mg absorbed
  • Delivery through permeable vessels at inflammatory sites is due to the concentration gradient. Consequently, due to higher plasma concentrations, Mobility HCC has a greater ability to localize in affected joints.

Importance of Chondroitin Sulphate

  • Chondroitin is the major cellular component of cartilage responsible for properties including resistance and elasticity
  • Chondroitin deficiency causes an inadequate supply of necessary cartilage components which leads to degeneration of the cartilage tissue
  • Hyaluronic acid and chondroitin work synergistically when administered together as hyaluronic acid is known to activate a receptor on the cartilage surface for the transfer of nutrients

Clinical Studies in Horses Using Oral Hyaluronic Acid

  • A study to evaluate joint effusion was conducted in 48 yearlings who underwent arthroscopic surgery for osteochondritis dissecans
    • 24 yearlings (27 joints) were treated with 100 mg hyaluronic acid daily for 30 days post-surgery
    • 24 yearlings (30 joints) were administered a placebo daily for 30 days post-surgery
    • A blinded examiner evaluated joint effusion on a scale of 0-5 (0 means no effusion)
    • The mean 30-day effusion score for the hyaluronic acid group was 0.67 while the placebo group was 2.05 (statistically significant P≤0.0001)
  • A study was conducted in 26 thoroughbreds in race training. They were given daily oral doses of placebo or 100 mg of hyaluronic acid for 59 days. Trainers were asked to observe
    • Days the horses were worked
    • Number of days just walked
    • Times referred to veterinarians for lameness exams or radiographs

On average, the treated group were galloped on the track for 5 extra days compared to placebo.

11 of the 13 horses in the placebo group were referred for lameness exam compared to 4 in the treated group.

Advantages of Oral Administration of Hyaluronic Acid

  • Use prophylactically to maintain joint health or prevent or limit joint disease
  • Oral absorption of hyaluronic acid provides support for all joints
  • Can lead to improvement in cartilage function
  • Can supplement hyaluronic acid in the joint fluid, increasing viscosity, reducing friction and enhancing the cushioning of the joint
  • Can supplement chondroitin sulphate in the cartilage to help with the ability to absorb water and avoid loss of elasticity
  • Hyaluronic acid and chondroitin sulphate work synergistically, being more effective than when given separately
  • Convenient administration in food with dosing 2-4 times yearly depending on activity level
  • Less intrusive than injection with the corresponding reduced risk of infection and needle damage to the surface of articular cartilage