Some things are simply better the second time around. We learn more, we know more and we see things differently. Such is the case with pentosan polysulfate (PPS).

This drug has been in use in Australia and parts of Europe for more than 30 years, and it's currently enjoying a surge in interest and use in the United States. Recent research focusing on its effects in horses has finally started to provide previously lacking scientific evidence for its specific beneficial impact as an antiarthritic agent in sport horses.

Initial uses

The properties of PPS were first investigated in sheep, dogs, rabbits, rats and chickens. Researchers noted a beneficial effect in cases of osteoarthritis in dogs, and sodium PPS was first approved as an injectable canine arthritis treatment in 1986 in Australia. It was next approved for the treatment of canine arthritis in New Zealand, the United Kingdom, Canada and Ireland. Since some of the initial studies also focused on use in people, PPS next gained approval as a human joint treatment throughout most of the European community, Scandinavia, South Africa and Australia.

No studies looking at the effects of PPS in horses had been done at that time, but the drug nonetheless began to be used to treat equine osteoarthritis, and claims both for and against its efficacy have circulated during the years. Good, intuitive reasons to expect PPS to function beneficially in horses have been around, as well as plenty of hard science and research in other species to point to, but the equine veterinary research community has been relatively slow to do the testing required to prove such claims.

Recent research and testing, however, have begun to provide horse owners with a much more complete understanding of the workings of PPS and have led to a renewed interest in this antiarthritic medication for sport horses in the United States.