Some Dog Supplements Lack Key Ingredients

Study finds some joint health supplements contain less of key ingredients than label says.

An independent study by has found some joint health supplements for dogs, cats and horses lack key ingredients.

Four of the six joint supplements selected and tested by were found not to contain the amounts of glucosamine or chondroitin advertised on the products’ labels. Glucosamine and chondroitin sulfate supplements are used to slow the progression of osteoarthritis, which is common in older dogs and cats as well as in horses.

The products that failed testing included a supplement for adult dogs, one for small dogs and cats, one for dogs and cats, and one for dogs and horses. Those supplements contained only 5.4 percent to 17 percent of the chondroitin or glucosamine claimed on their labels, according to the study.

No problems were found with the MSM (methylsulfonylmethane) content. MSM is used primarily for treating pain associated with osteoarthritis. In the veterinary industry, MSM is used to treat muscle and tendon soreness, pain, and inflammation in horses, according to the study.

No products exceed contamination limits for lead.

Through’s Voluntary Certification Program an additional 10 products were tested at the request of manufacturers or distributors. All of those products were found to meet quality standards, according to the study. is a privately held company based in Westchester, N.Y., that provides consumer information and independent evaluations of products affecting health and nutrition.

Article Categories:
Dogs · Health and Care