In the case of dogs the "pusher" is not a person hanging around on a corner, wearing gang colors, but a toad. Certain toads produce poisonous substances as part of their . This results in their skin becoming poisonous. In addition they also have parotoid glands behind their eyes which produce a substance which mixes with their sweat or any water on their skin to form a solution that is poisonous enough to kill a grown dog. It is because these toad venoms contain digoxin-like cardiac glycosides, that the ingestion of this fluid can be fatal. An example of such a poisonous toad in America is the Colorado River toad which is also known as the Sonoran Desert toad. However the most widespread poisonous species is the cane toad, which is native to South America, but has been introduced into a number of Caribbean countries, and also into Australia. The importing and release of these toads was done as a pest control measure. Cane toads have a voracious and love to eat the beetles that devastate sugarcane fields (hence the name "cane toad").

Bufotenine, the hallucinogenic component of the toad venom, is a controlled substance that is legally in the same class as things like LSD and is therefore outlawed in many places. There have been many cases mentioned in the press of people arrested for its use. Thus the New York Times Magazine carried a story in 1994 about a California teacher who became the first person to be arrested for possessing the venom of toads. In 2007 a man in Kansas City was charged with possession of a controlled substance after authorities determined that he intended to use toad venom to get high. Over the ensuing years a number of other stories appeared about people extracting bufotenine from toads and preparing it in a form which could be smoked in order to have the psychedelic experience.

So where do dogs enter this picture? Apparently dogs licking these dangerous toads is a worldwide problem, however there appears to be an epidemic of it in Queensland Australia. You see, apparently the toad secretions taste sweet. So it appears that some dogs first lick a toad because, like all dogs, they have a fondness for sweetness. What follows (if the dog survives) is a hallucinogenic experience. Apparently some dogs become addicted to these psychedelic effects, and veterinarians in Queensland are reporting an increasing number of canine repeat offenders, which they dub "serial lickers," since these animals are being treated for cane toad poisoning several times a year.

Australian veterinarian, Megan Pickering has said, "The phenomenon of animals deliberately getting intoxicated by cane toads is fascinating. It just seems unbelievable that an animal will go back for a second try. But nevertheless we do have many documented cases of patients who deliberately—on a regular basis—will seek out a toad and they seem to be able to lick the toad in such a way that they seem to get a very small dose."

Pickering and other vets warned that some dogs are so desperate for a fix that they deliberately hunt down these particular toads to stimulate the excretion of the deadly poison, which they can then lick from their prey. Unfortunately, like all addicts, these dogs are risking their lives for their cheap thrill.

Stanley Coren is the author of many books including: The Wisdom of Dogs; Do Dogs Dream? Born to Bark; The Modern Dog; Why Do Dogs Have Wet Noses? The Pawprints of History; How Dogs Think; How To Speak Dog; Why We Love the Dogs We Do; What Do Dogs Know? The Intelligence of Dogs; Why Does My Dog Act That Way? Understanding Dogs for Dummies; Sleep Thieves; The Left-hander Syndrome

Copyright SC Psychological Enterprises Ltd. May not be reprinted or reposted without permission