Mar Vista Animal Medical Center

3850 Grand View Blvd.
Los Angeles, CA 90066




(for veterinary information only)







joint diagram 

(original graphic by

A joint consists of articulating bones, a fibrous capsule enclosing the joint, and slippery lubricating joint fluid to facilitate the gliding of the two bones across each other when the joint is flexed.

The articulating bones are capped by cushions of cartilage to facilitate this frictionless gliding. The integrity of the smooth, somewhat soft cartilage is crucial to normal range of motion and comfort. Approximately 95% of cartilage consists of material called "cartilage matrix," the other 5% being the cells that produce the matrix.  Cartilage matrix consists of collagen (the tough structural fibers that most people have heard of) and proteoglycans (the water absorbent molecules most people have not heard of). A proteoglycan’s function is to soak up water thus creating a plump soft cushion, sort of like a water bed, to absorb the pressure exerted on the joint as it works. A proteoglycan molecule looks something like a bottlebrush: it has a long “handle” (the “proteo” part) and long bristles called glycosaminoglycans (or GAG’s) which soak up the water.

Over years, either through injury or poor conformation, cartilage wears down or is damaged and arthritis results. The body must then make more matrix and will require the raw materials to do so. Polysulfated GAG’s may be injected into the body where they will be distributed to any joints currently effecting cartilage repair.

It turns out, however, that polysulfated GAG’s represent more than just building materials. They have anti-inflammatory properties of their own which helps slow down the actual damage to the cartilage. They also promote enzyme systems that facilitate other aspects of joint repair beyond simply making more matrix. They help the joint create more lubricating fluid as well.

illustration of Proteoglycan
Proteoglycan depiction: core proteins in green,
GAG "bristles" in red, hyaluronic acid in blue.

(original graphic by

The active ingredient in Adequan® is polysulfated GAG (mostly chondroitin sulfate) extracted from cow tissue (the trachea, to be exact).



In treating arthritis, injections are given twice a week for 4 weeks for a maximum of eight injections. Injections are given intramuscularly. Dogs, cats, and horses are the usual patients.

There is another more controversial use for this medication and that is in the treatment of Feline Idiopathic Cystitis. One of the theories of this very complicated syndrome is that the GAG’s which line the urinary bladder and help protect the bladder tissue from the irritating urine it holds become depleted. By giving a GAG injection, they may be restored thus helping to resolve the urinary discomfort associated with this syndrome. At present, it is not clear if this treatment is effective.



In a study of 24 dogs receiving injections, one developed a painful injection site, one developed diarrhea, and one developed a tendency toward increased bleeding. All side effects were classified as mild and none required treatment.



None known, in fact, it seems to make an excellent combination with other arthritis treatments for pets.



This medication has not been studied in pregnant or lactating animals.

Because polysulfated GAG’s are similar in structure to the anticoagulant, heparin,
they should not be used in patients with known bleeding disorders.
In studies where 25 times the recommended dose was used,
bleeding tendencies of serious consequence did occur.

When doses of approximately 7x the recommended dose were used, normal dogs developed enlarged kidneys. Because of this, caution is recommended when using this product in patients with kidney disease.

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Page last updated: 11/21/2021