Retired athletes in the NFL and NBA have recently called on major league sports to let players treat aches and pains with medical marijuana. That made us wonder if competitors in the 2016 Kentucky Derby - which takes place this weekend (May 6-7) - could benefit from medicinal cannabis. And we mean the horses, not the jockeys.

It turns out that cannabis could benefit horses in the same way it helps humans with arthritis and other joint issues. And taking care of these conditions in horses might not only improve their quality of life, but also save them from being euthanized.

In 2013, the American Veterinary Medicine Association (AVMA) - an industry association representing more than 88,000 vets nationwide - profiled the case of Phoenix, a 20-year-old Paso Fino who had a degenerative ligament disease. When her condition no longer responded to conventional drugs and treatments in 2012, Phoenix stopped walking, eating and drinking. That forced her owner - California resident Becky Flowers - to consider euthanizing Phoenix to spare her from suffering.

Horse owner tried cannabis after other drugs fail

But Flowers wanted to try one more treatment first. Since marijuana had helped treat her own pain from spinal spurs and arthritis, Flowers wondered if it could help her steed as well. So she cooked up some cannabutter and fed it to her horse once a day. She says Phoenix regained mobility and a healthy appetite right away. (Yes, horses get the munchies too).

The experience turned flowers into an advocate for cannabis as not only an effective treatment but a better medicine for horses than conventional drugs.

"With cannabis, I don't worry about potential liver damage," says Becky Flowers. "I also don't worry about her overdosing, as I only give her a small amount. She never appears panicky or disoriented. She's just her normal, happy Phoenix."

Now scientists are studying the merits of Flowers' anecdotal evidence in support of veterinary cannabis. Two years after the story of Phoenix surfaced, Peak Pharmaceuticals - a cannabis lab in Colorado - announced plans to study the effects of cannabinoids on horses suffering from joint pain and anxiety.

This could be the latest case of medical researchers rediscovering cannabis' medicinal value. In an article written for PETA in 2013, Amanda Reiman of the Drug Policy Alliance (DPA) noted that using cannabis to treat horses may have originated in ancient Greece, where classical physicians mixed various herbs - including cannabis - into a poultice applied to a horse's wounds.

Horse owners in California can now get a similar treatment called "Lame Away," which uses non-psychoactive cannabinoids, so the horse benefits from pain relief and an increased appetite without the disorienting effects of marijuana.

h/t Quartz