Creature Companion 2016; June: 54-55.
Anton C. Beynen
Green-lipped mussel and curcumin in mobility foods for dogs
Mobility impairment is a common canine disease. Dogs are reluctant to walk, run and jump, and
may show lameness. The cause often is breakdown of cartilage in joints. This implies loss of shock
absorber that allows the joint to move smoothly. The ends of the bones begin to rub together,
evoking pain. Damaged tissue elicits the release of inflammatory substances, contributing to pain
and swelling of the joint. The condition is called osteoarthritis.
There are dog foods, snacks and nutritional supplements making joint- health claims, whereas
therapeutic mobility foods purport to reduce clinical signs of osteoarthritis. These products are
marketed on the basis of a wide variety of joint-protective constituents. Among these agents are
powders derived from the New-Zealand green-lipped mussel and preparations of curcumin, which
is a component of the yellow spice made from turmeric stem.
For demonstration of the efficacy of a potential joint-improving agent, a double-blinded, placebo-
controlled trial in dogs with osteoarthritis is required. The placebo has no real effect and
treatment identity is kept from both owner and investigator. In this way, the trial design takes into
account the impact, if any, of biased evaluation and spontaneous course of disease. In placebo-
treated dogs with osteoarthritis there often is perceived improvement over time.
Studies on the efficacy of green-lipped mussel either had inadequate design or unconvincing
results for its application in the management of canine osteoarthritis. There is no comfortable
evidence that mobility foods containing either green-lipped mussel or curcumin reduce clinical
signs of osteoarthritis in dogs.
Green-lipped mussel and curcumin
Powdered preparations and oily extracts of the New Zealand green-lipped mussel (Perna canaliculus)
have anti-inflammatory properties in model systems. In-vitro studies indicate that curcuminoid
derivatives reduce inflammation and inhibit collagen degradation in cartilage. Thus, there are clues
to a beneficial effect of green-lipped mussel and curcumin in the treatment of canine osteoarthritis,
but solid evidence can only come from well-designed clinical trials.
Trials on green-lipped mussel
Oral administration of a green-lipped mussel preparation reportedly improved clinical signs in
arthritic dogs (1), but the study was open and non-controlled. Putting green-lipped mussel powder
on top of food or incorporating it into a treat significantly improved dogs’ arthritis scores over 6
weeks (2). The dose was equivalent to 139 mg/MJ of metabolizable energy as calculated for a 35-kg
dog. The two experiments were designated as double-blind and controlled, but no control topping
was used and it is uncertain whether the control and test treats were indistinguishable. Moreover,
the magnitude of the effects can be considered meaningless.
In a double-blinded, placebo-controlled study, oral delivery of green-lipped mussel extract (53
mg/MJ for 12 weeks) did not affect clinical signs in dogs with osteoarthritis (3). Another masked and
controlled trial showed that ingestion of freeze-dried green-lipped mussel (139 mg/MJ for 8 weeks)
significantly improved mobility (4). The median improvement versus baseline was 1 on a 0-24 scale
and 0.2 on a 0-10 scale for the assessment by veterinarians and owners, respectively. This calls into
question the clinical relevance of the statistically significant increase in mobility.
A double-blinded, placebo-controlled trial concluded that oral treatment with a green-lipped mussel
extract (139 mg/MJ for 8 weeks) improved the arthritis score in dogs with osteoarthritis (5), but the
baseline scores for control and test group were different, whereas the negative slopes of the score
time courses were similar. In an open, non-controlled study, the intake of green-lipped mussel oil
was associated with less lameness in dogs with osteoarthritis (6).
Trials on curcumin
A complex mixture including curcumin (7) and an extract of two turmeric species (8) have been
evaluated in canine osteoarthritis. The extract (17 mg curcumin plus desmethoxycurcumin/MJ for 8
weeks) was tested in a double-blind, placebo-controlled trial (8). The investigators’ and owners’
overall assessments were in favor of curcumin, but lameness, pain on joint manipulation and kinetic
gait pattern appeared unaffected. A high proportion (19/24) of curcumin-treated dogs emanated
malodor through their skin, urine or feces. This effect may have compromised the blinded nature of
Therapeutic mobility foods
Three studies (2, 9-11) have addressed the efficacy of a therapeutic mobility food containing green-
lipped mussel. The kibbles were coated with freeze-dried powder at a final inclusion level of 0.3% (2,
9, 10). One study was open and uncontrolled (10). The other two studies were blinded, but had a
longitudinal instead of parallel control (2, 9, 11) so that time effects cannot be excluded. An
improvement of the dogs’ arthritic scores was claimed (2, 9). Apart from the flawed study design,
the improvement was 4 on a 0-196 scale, which is clinically irrelevant.
Dogs suffering from osteoarthritis were fed a therapeutic food supplemented with curcuminoids
extract, hydrolysed collagen and green tea extract for 3 months (12). Clearly, curcumin was not the
sole additive. The study was named double-blinded and placebo-controlled, but effective blinding is
questionable. Curcumin probably colored the test food yellow, stained the owners’ hands and
caused dogs to generate malodor. The therapeutic diet diminished some kinds of pain, but did not
improve lameness and mobility. The study is wrongly cited in substantiation of the food’s advertising
slogan: “Visible improvements to mobility, activity and quality of life” (13).
1. Korthäuer W, De la Torre J. Behandlung deformierender Arthopathien beim Diensthund mit einem
neuen Glykosaminoglykanpräparat. Kleintierpraxis 1992; 37: 467-478.
2. Bierer TL, Bui LM. Improvement of arthritic signs in dogs fed green-lipped mussel (Perna
canaliculus). J Nutr 2002; 132: 1634S-1636S.
3. Dobenecker B, Beetz Y, Kienzle E. A placebo-controlled double-blind study on the effect of
nutraceuticals (chondoitin sulfate and mussel extract) in dogs with joint disease as perceived by their
owners. J Nutr 2002; 132: 1690S-1691S.
4. Hielm-Björkman A, Tulamo R-M, Salonen H, Raekillio M. Evaluating complementary therapies for
canine osteoarthritis Part I: Green-lipped mussel (Perna canaliculus). eCAM 2009; 6: 365-373.
5. Pollard B, Guilford WG, Ankenbauer-Perkins KL, Hedderley D. Clinical efficacy and tolerance of an
extract of green-lipped mussel (Perna canaliculus) in dogs presumptively diagnosed with
degenerative joint disease. N Z Vet J 2006; 54: 114-118.
6. Mongkon N, Soontornvipart K. Preliminary study of the clinical outcome of of using PCO-524
polyunsaturated fatty acid compound in the treatment of canine osteoarthritis and degenerative
spinal diseases. Thai J Vet Med 2012; 42: 311-317.
7. Moreau M, Lussier B, Pelletier J-P, Martel-Pelletier J, Bédard C, Gauvin D, Troncy E. A medicinal
herb-based natural health product improves the condition of a canine natural osteoarthritis model:
A randomized placebo-controlled trial. Res Vet Sci 2014; 97: 574-581.
8. Innes JF, Fuller CJ, Grover ER, Kelly AL, Burn JF. Randomised, double-blind, placebo-controlled
parallel group study of P54FP for the treatment of dogs with osteoarthritis. Vet Rec 2003; 152: 457-
9. Bui LM, Bierer TL. Influence of green lipped mussels (Perna canaliculus) in alleviating signs of
arthritis in dogs. Vet Therapeutics 2003; 4: 397-407.
10. Servet E, Biourge V, Marniquet P. Dietary intervention can improve clinical signs in osteoarthritic
dogs. J Nutr 2006; 136: 1995S-1997S.
11. Rialland P, Bichot S, Lussier B, Moreau M, Beaudry F, Del Castillo JRE, Gauvin D, Troncy E. Effect
of a diet enriched with green-lipped mussel on pain behavior and functioning in dogs with clinical
osteoarthritis. Can J Vet Res 2013; 77: 66-74.
12. Comblain F, Barthélémy N, Lefebvre M, Schwartz C, Lesponne I, Serisier S, Feugier A, Balligand M,
Henrotin Y. Randomized, double-blinded, controlled clinical trial evaluating the efficacy of a diet
supplemented with curcuminoids extract, hydrolyzed collagen and green tea extract in dogs
suffering from osteoarthritis. Osteoarthritis Cart 2016; 24: S353.
13. Advertisement (A leap forward in mobility management). Vet Pract 2015; 47(9): 5.