Hydrolyzed collagen peptides, types I and III, are the material your dog's cruciate ligament is made of. Type I is the rope itself, the fibers that hold the shin in place with every step. Type III is the repair tissue laid down where fibers fray. Hydrolyzed means already broken down into small peptides, so they're in the blood the same day.

The cruciate ligament is mostly type I collagen, and its core has almost no blood supply of its own: it's fed by diffusion, by what circulates each day. In a 12-week trial in dogs, daily collagen peptides significantly improved the force dogs put through their leg, measured on a force plate, and their quality of life, while an omega-3 group did not. This is the ingredient hip and joint chews leave out.

UC-II® is a patented form of undenatured type II collagen, the collagen of joint cartilage. In a knee whose ligament is fraying, the cartilage and meniscus take the extra load. UC-II® works through oral tolerance, teaching the immune system not to attack the joint's own collagen.

40mg a day is the dose used in dog studies of UC-II®, including a trial in 50 dogs recovering after cruciate surgery, where the supplemented dogs walked with an even gait at 12 weeks instead of 24. Every 1 mL of Pawlity delivers that 40mg, so a 2 mL dose gives a large dog twice the studied amount.

Quercetin is a naturally occurring flavonoid with anti-inflammatory properties. Inside a loaded, fraying knee, inflammation is constant, and it releases the enzymes that digest collagen. Quercetin calms that upstream, without the long-term side effects of daily painkillers.

Quercetin stabilizes the cells that release inflammatory messengers and inhibits several of the enzymes (matrix metalloproteinases) that break collagen down. Less collagen digested is more rope left standing while the new fibers are laid down. It pairs with collagen: one feeds the structure, the other protects it.

Bromelain is a natural enzyme extracted from pineapple stems. It plays two roles in our formula: it boosts the uptake of quercetin, so the active dose actually reaches your dog's system, and it has its own anti-inflammatory action, helping to break down inflammatory proteins around a sore joint.

Quercetin on its own is poorly absorbed. Bromelain improves its uptake in the gut, multiplying its effect. This is the classic pairing used in human joint and recovery formulas, now dosed for dogs.

DHA and EPA are the marine omega-3 fatty acids. In a knee under constant load, the joint lining stays inflamed, and that inflammation is what releases the enzymes that digest collagen. Omega-3s calm it from the inside while the collagen does the building.

EPA and DHA are built into cell membranes, where they produce resolvins and protectins, the molecules that switch inflammation off. Omega-3 is the one nutraceutical veterinary guidelines rate as effective for joint pain and mobility in dogs. In this formula it protects the rope while it's being fed.

Colostrum is the first nourishment produced by mammalian mothers after birth, rich in immunoglobulins and growth factors. Those growth factors support the repair of connective tissue, and the immunoglobulins keep the immune system balanced during a long recovery.

Colostrum contains IGF-1 and TGF-beta, growth factors involved in the repair of tendon and ligament tissue, plus IgA immunoglobulins that support the gut lining, where every nutrient in this bottle is absorbed. A dog that absorbs well is a dog whose ligament gets fed. Bovine-derived: if your dog is dairy-sensitive, check with your vet.

MSM (methylsulfonylmethane) is a natural source of organic sulfur, a mineral the body needs to produce collagen and connective tissue. It also has anti-inflammatory properties, easing a sore joint while the collagen does its slower work.

Sulfur is the third most abundant mineral in a dog's body and an indispensable cofactor in collagen synthesis. Without enough sulfur, the cells in the ligament can't cross-link new fibers into a rope that holds. MSM supplies bioavailable sulfur and inhibits pro-inflammatory cytokines at the same time: raw material for the build, and less fire while it happens.

Astragalus is an adaptogen used for millennia in traditional medicine. It helps the body keep its immune response proportionate, which matters over the months a ligament takes to be fed, when a dog is often also on pain medication and short on exercise.

Astragalus polysaccharides and saponins modulate T-lymphocyte activity, supporting a balanced rather than overactive immune response. In a joint that has been inflamed for months, that balance is part of letting the repair happen instead of the breakdown.

Vitamin C is the cofactor without which the body cannot assemble collagen at all. Feeding peptides without vitamin C is delivering bricks with no mortar. It's the trigger that turns the collagen in this bottle into new ligament fibers.

Vitamin C is required for the hydroxylation of proline and lysine, the two reactions that stabilize the collagen triple helix. Without it, the collagen produced is weak and unstable. In a human trial, gelatin taken with vitamin C before exercise doubled the markers of collagen synthesis. It also protects existing collagen from the free radicals a chronically inflamed joint produces.

Zinc is an essential mineral for tissue repair and collagen synthesis. It's involved in the enzymes that clear damaged fibers and in the cell division that lays down new ones. Low zinc means slow repair, and a ligament under load can't afford slow.

Zinc takes part in over 300 enzymatic reactions, many of them in connective tissue repair. It's a cofactor of the collagen-building enzymes and of the cells (fibroblasts) that produce ligament fibers. A zinc shortfall measurably slows the healing of connective tissue.

Biotin (vitamin B7) supports coat and skin health. It isn't there for the knee. It's there because a dog in months of recovery, on less exercise than usual, should still look like himself, with a coat that says he's doing fine.

Biotin is a cofactor in keratin production, the structural protein of hair and the outer skin layer. Supplementation supports coat density and shine. A side benefit, and the one owners notice first around week three.

Vitamin E is a fat-soluble antioxidant that protects cell membranes from free radicals. A joint that has been inflamed for months produces an excess of them, and they attack collagen. Vitamin E shields the fibers being laid down while the rope is fed.

Free radicals generated by chronic inflammation attack collagen cross-links and accelerate breakdown. Vitamin E intercepts them in the cell membrane. Its effect is synergistic with vitamin C: one drives new collagen production, the other protects both the old fibers and the new ones.

Hyaluronic acid is the molecule that gives joint fluid its slipperiness. A trace amount rounds out the formula. It is not the hero here: the hero is the collagen that the ligament is made of.

Hyaluronic acid can hold up to 1,000 times its weight in water and is a natural component of synovial fluid, the lubricant of the knee. In this formula it plays a supporting role next to collagen, vitamin C and UC-II, the three ingredients that address the ligament and the cartilage of the same joint.