Question and design

42 client-owned dogs enrolled; 35 completed to day 70. A multi-ingredient glucosamine/chondroitin supplement for 70 days. Comparator: Carprofen; no untreated placebo arm.

What was measured?

Veterinarians’ subjective pain, mobility, lameness, weight-bearing and overall-condition scores.

Main findings

Several supplement-group scores improved from baseline by day 70. Two supplement-group dogs withdrew with gastrointestinal reactions.

Strengths and limitations

Blinded assessments, an active comparator and repeated visits. Although titled randomised, allocation alternated by recruitment order. Subjective outcomes, attrition and no untreated placebo limit causal interpretation. The supplement contained additional ingredients.

Researchers’ conclusion

The authors interpreted the combination as clinically beneficial.

Evidence.pet interpretation

A non-significant difference from an active drug is not proof of equivalence. Baseline improvement without an untreated control also leaves alternative explanations. The tested combination cannot validate unknown amounts in a food.

Funding and conflicts

VetPlus supplied financial support; BSAVA Petsavers supported a residency.

Source and connected records

McCarthy G, O’Donovan J, Jones B, McAllister H, Seed M, Mooney C. Randomised double-blind, positive-controlled trial to assess the efficacy of glucosamine/chondroitin sulfate for the treatment of dogs with osteoarthritis. Veterinary Journal. 2007;174:54–61.

Read the primary source · DOI record

glucosamine · chondroitin sulfate

STU-026. Checked 24 September 2026. Next review 24 December 2026. Full-text editorial appraisal; substantial design limitations.