Best joint supplement for senior dogs.

A disclosed green-lipped-mussel-forward chew, NASC-sealed and well priced; a modest GLM dose for a larger dog keeps it Good rather than Strong.

The senior version of YuMOVE's green-lipped-mussel chew, fully disclosed with the same ActivEase GLM backbone plus added omega-3, hyaluronic acid, and vitamins C and E, from an NASC, batch-testing brand; the GLM dose is modest and its evidence is moderate rather than strong, so it lands Good not Strong, but it is fairly priced at about 0.42 a day.

Excellent dose transparency and in-house batch testing on a weakly-evidenced active; in our view it lands Good, not Strong, because glucosamine and chondroitin evidence for osteoarthritis is contested.

A distinct soft-chew Cosequin that discloses every active with no blend and adds omega-3, from a maker that owns its US plants with a clean recall record; the glucosamine and chondroitin evidence is weak and the long-term maintenance schedule under-doses a small dog, but at about 0.42 per day it is fair value.

Top-tier dose transparency (adds ASU and boswellia) and batch testing, but the headline glucosamine and chondroitin evidence is weak and cost per day is mid; Good.

The reference-weight Dasuquin: glucosamine, chondroitin, ASU, and MSM fully disclosed and batch-tested, but the headline glucosamine and chondroitin evidence is weak; Good.

Green-lipped mussel is the better-evidenced joint active and the label discloses every amount with no blend, from an NASC brand that owns its plant, but a 22 lb dog sits at the low end of the weight-scaled schedule so its per-day green-lipped mussel lands under typical studied doses, and there is no independent testing.

The mid-stage GlycoFlex, fully disclosed with green-lipped mussel alongside glucosamine and MSM, from an NASC brand that owns its plant; green-lipped mussel is the better-evidenced joint active but the weight-scaled schedule keeps a small dog's per-day dose modest, so it lands Good rather than Strong, with no independent testing named.

A fully disclosed dog-and-cat joint chew from an NASC founding member that owns its Vermont plant, with glucosamine, chondroitin, and green-lipped mussel and a hedged support claim, and it is very cheap per day; the catch is the familiar one, the glucosamine evidence is weak and the per-serving dose is modest, so it lands Good on execution rather than Strong on proof.

Fully discloses its per-active amounts from a clean-record NASC brand at a fair price, but chondroitin is a token 100 mg behind the 500 mg glucosamine and there is no independent batch testing; the glucosamine and chondroitin evidence itself is weak.

Discloses a strong glucosamine and chondroitin dose plus ASU and omega-3 from a maker that owns its cGMP plant with a clean recall record; the glucosamine and chondroitin evidence is weak, a 140 mg botanical blend hides four secondary amounts, testing is in-house, and the vet-channel price runs high.

A fully disclosed green-lipped-mussel chew, NASC-sealed, but in our view the headline 41% strength claim overreaches its evidence, which pulls Evidence down to Mixed.

NASC-sealed and heavily marketed, but a proprietary blend hides the per-active doses and the cost per day is high, so it lands in Limited.