Efficacy of Intramuscular Chondroitin Sulfate and Compounded Acetyl-d-Glucosamine in a Positive Controlled Study of Equine Carpitis☆

Summary

Thirty healthy lameness-free horses were subjected to the Complete Freund's Adjuvant (CFA) (Sigma, St Louis, Mo) carpitis model, which was allowed to develop for 5 days. The horses were then stratified by model-induced deficit in lameness score, carpal flexion, stride length, and carpal circumference, and they were randomly assigned to 3 groups of 10 horses. The horses were treated with one of 3 treatments beginning on day 5: Group A (positive control) received PSGAG (Adequan, Luitpold Pharmaceuticals, Inc, Shirley, NY); Group B received a compounded solution of acetyl-d-glucosamine (Red Cross Drug, Blanchard, Okla); and Group C received a solution of chondroitin monosulfate (Chondroprotec, Neogen Corp, Lexington, Ky). All horses received the treatments by intramuscular injection every 4 days for 4 weeks and all doses were 500 mg/5 mL. On days 12, 19, 26, and 33, the primary outcome measures were taken for lameness score, carpal flexion, stride length, and carpal circumference. The study was blinded because the clinician evaluating the outcome measures was unaware of the treatment group assignments. The group means for percent recovery of model-induced deficits in these parameters was subjected to statistical analysis.

PSGAG was significantly (P < .05) more effective in the recovery of model-induced deficits in all parameters than were chondroitin and glucosamine injectable solutions, and there was no significant difference between the 2 test drugs. In this test system, these 2 compounds, often sold as “generic” versions of PSGAG, were significantly less effective than PSGAG.