Dogs experience 'runner's high' like humans

This may be the reason why dogs love to 'fetch'!
Dogs experience a "high" from running, similar to the 'runner's high' felt by people who run or jog frequently, a new study has found.
The study published in The Journal of Experimental Biology, described that researchers measured neurotransmitter levels in humans, dogs and ferrets as they moved on a treadmill to determine neurobiological reward levels.
Scientists have found that sensations of "runner's high" are due to the release of neurotransmitters into the bloodstream - one of these neurotransmitter groups, known as endocannabinoids (eCBs) have the same chemical structure as THC, the chemical responsible for the high people get from marijuana.

Researchers tried to determine if other animals also experience a runner's high, website phys.Org reported.
The team enlisted some human volunteers, several dogs and some ferrets. Each was put on a treadmill set at a pace fast enough to simulate running.

Afterwards blood samples were taken. The results showed elevated levels of eCBs for both the humans and dogs, but not in the ferrets.
In another test, the researchers slowed the pace of the treadmill to just a walk for the dogs and humans and found no change in eCB levels.
The researchers noted that both humans and dogs are part of a group known as cursorial animals - animals that have long legs meant for running.

Ferrets on the other hand, are not cursorial, thus they don't gain any pleasure from running long distances.
The researchers believe that neurobiological rewards are a part of the evolutionary history of animals with long legs meant for running and strong lungs-they helped keep them fit.
Running, particularly when not necessary, they suggest, kept such animals in good shape allowing them to escape predators and to hunt efficiently.