Answered by: James L. Cook, DVM, PhD, DACVS, DACVSMR:
Glucosamine does not help prevent hip dysplasia at all nor does it help treat hip dysplasia in and of itself as hip dysplasia is a developmental problem of hip joint laxity and subsequent malformation. The combination of glucosamine and chondroitin sulfate is effective as part of a treatment plan for secondary osteoarthritis, which is common in dogs with hip dysplasia.