Eighty-one (81) dogs suffering from mild to severe joint disease were supplemented for 112 days (between June 1997 and October 1998) either with New Zealand green-lipped mussel extract or placebo in a clinical trial at the Institute of Veterinary, Animal and Biomedical Sciences (IVABS) at Massey University, Palmerston University North, New Zealand.
The research group of seven investigators was headed by Professor W. Grant Guilford, Head of the IVABS. The study was designed in two parts. The first 56 days were double-blinded study, where both the owners of the dogs and the veterinary clinical investors undertaking the clinical assessment were blinded to the treatment with the mussel extract or the placebo. In the second part of the trial all dogs were placed on mussel extract from 56 to 112 days. An assessment of the dogs´ condition (lameness, weight bearing, joint mobility, willingness to hold up contralateral limb and pain) was made by the owners as well as the veterinaries, and in addition several biochemical and haematological measurements, relevant to arthritis and other chronic degenerative joint disease were made.
The overall result of the study was that New Zealand green-lipped mussel extract supplementation improves joint disorders in dogs in an average of 74 per cent. Until day 28 of supplementation, in both groups (mussel extract and placebo), an improvement in about 40 per cent of the dogs was observed both by owners and veterinary clinicians.
This is explained partly by natural healing and partly the placebo effect. In the placebo group, however, no further improvement was noted after this point of time, whereas in the mussel extract group the percentage of the dogs improving increased until 74 percent. When the dogs which had been on placebo until day 56, were put on mussel extract supplementation, the percentage of healing increased to an average of 91 per cent. The degree of agreement between the owners and the clinicians on improvement of the clinical condition of the dogs was very good, and suggested that, in general, treatment of arthritic disorders in pets may be determined as being successful or unsuccessful on the basis of owner observations.
This study confirms the results obtained earlier in a multicenter study conducted by veterinary clinics in Japan, where 90 per cent of dogs and cats suffering from arthritis improved when supplemented with New Zealand green lipped mussel extract.