What Is 'Frog Juice?'
A waxy monkey tree frog sitting on a branch.
Credit: Katrina Brown | Shutterstock

Covering the back of South America's waxy monkey tree frog (Phyllomedusa sauvagei) is a painkiller 40 times more powerful than morphine, and apparently, a racehorse prodder. The amphibian secretion has now shown up in the bloodstreams of 30 racehorses in four U.S. states, according to an article in the New York Times.

The substance, called dermorphin, blocks pain while increasing feelings of excitation and euphoria, all of which would prod a horse to run faster and harder despite injuries.

This isn't the first time a useful substance has been found in frogs.

Frogs, like other amphibians, have highly permeable skin that allows them to breathe through their skin. This capability means their skin is also sensitive. As such, frogs have developed various skin secretions that kill microbes and other pathogens. These same secretions have useful human-health properties, from powerful antibiotic features to anti-cancer powers.

Since the drug can impact the outcome of horse races, the recent finding is a serious drug violation for the industry, the NYT reports.

In fact, on Saturday (June 17), stewards at Louisiana's Delta Downs suspended quarter horse trainer Alvin Smith Jr. for six months after Dashin Forward — second-place winner in a race on May 26 — tested positive for dermorphin, according to nola.com of The Times-Picayune. The horse was disqualified and his winnings, more than $38,000, will be re-distributed.

The horse trainers or their suppliers are likely not squeezing loads of waxy frogs, and instead are likely getting their "frog juice" from synthetic creations of the substance, the NYT reports.

Figuring out the prevalence of dermorphin use in racehorses is tricky, as many states don't even have the capability to test for it.

"It's a cat-and-mouse game. As soon as you call out dermorphin, they will try something else. That is the daily battle that goes on," Edward J. Martin, president of Racing Commissioners International, a trade association for racing regulators, said in the NYT article.

Read more on dermorphin at the New York Times.