1. Laika First Animal to Go Space

Fifty years ago this Saturday, Laika -- a sweet-tempered stray plucked off the streets of Moscow -- was thrust into the global spotlight when she became the first living creature sent into space. 

When Sputnik 2's canine passenger (nicknamed "Muttnik" by the media) hit orbit, the Soviet Union grabbed the edge over the U.S. in the space race, a crux of competition during the Cold War.

Sadly, Laika's history-making voyage ended prematurely: In their rush to be first, Soviet scientists had made no provisions for her safe return.

"She died before reaching orbit, and before any real data was gleaned about sustaining life in that environment," says Dr. Stanley Coren, professor of psychology at the University of British Columbia and author of "The Pawprints of History: Dogs and the Course of Human Events."

But if little scientific knowledge was gleaned from Laika's journey, her mark on world events is undeniable. "We were behind the Russians," says Coren. "The U.S. quickly switched focus to putting a living being on the moon."

2. Strelka and Belka's successful orbit

Laika was the first dog sent into space, but Strelka (Little Arrow) and Belka (Squirrel) -- launched on Sputnik 5 in 1960 for a one-day mission -- were the first to return alive. As a result, much more was learned from their mission. Strelka later gave birth to a litter of puppies, one of which, Pushinka, was given to President John F. Kennedy's daughter, Caroline.

3. How Peritas saved civilization

Without his dog, Peritas, Alexander the Great might have been Alexander the So-So. When the warrior was swarmed by the troops of Persia's Darius III, Peritas leapt and bit the lip of an elephant charging his master. Alexander lived to pursue his famed conquest, forging the empire underlying Western civilization as we know it.

4. Charlie, Kennedy's Cuban Missile Crisis companion

At the height of 1962's Cuban missile crisis, President Kennedy had his son's Welsh terrier Charlie summoned to the chaotic War Room. The president held the terrier in his lap, petting him and appearing, by all accounts, to relax. Eventually he announced that he was ready to "make some decisions" -- those that de-escalated the conflict.

5. Jofi, the first therapy dog

Sigmund Freud usually kept a chow named Jofi in his office during psychotherapy sessions, believing the dog comforted the patients. Freud's notes on these interactions, detailed in his diaries, form the basis of modern-day pet-assisted therapy.

6. Urian bites Pope, separates church and state

Henry VIII sent Cardinal Wolsey to meet with Pope Clement VII, hoping the pontiff would grant the ruler an annulment of his marriage to Catherine of Aragon. When the pope extended his bare toe to be kissed (as was the custom) by Wolsey, the Cardinal's dog, Urian, sprang forward and bit the pope. Clement flew into a rage, the divorce was off and Henry -- to ensure the annulment the Catholic Church refused to grant -- later established the Church of England.

7. Newfoundland saves Napoleon

Napoleon Bonaparte owed his life to a nameless Newfoundland. As Bonaparte fled the island of Elba in 1815, where he was exiled, choppy seas pitched him overboard. A fisherman's dog jumped in after the drowning despot and kept him afloat. Napoleon lived to experience his own defeat at the Battle of Waterloo.

8. Nixon professes love for Checkers

In his 1952 "Checkers speech," Richard Nixon -- then a candidate for vice president who was accused of pawing $18,000 in illegal campaign contributions -- admitted to accepting an American cocker spaniel, Checkers, as a gift.

"And you know, the kids, like all kids, loved the dog, and I just want to say this, right now, that regardless of what they say about it, we are going to keep it," Nixon said during his famous speech.

His heartfelt proclamation swayed public opinion and prolonged Nixon's political career.

9. Peps, Wagner's harshest critic

Without Peps, composer Richard Wagner's Cavalier King Charles spaniel, that helicopter scene in the film "Apocalypse Now" (scored to "The Ride of the Valkyries") might sound very different. Wagner would have Peps sit on a special chair as he played his latest compositions and, based upon the dog's reactions, he'd keep or toss each passage.

10. Donnchadh and the American Revolution

In 1306, when Edward I of England sought to bring down Robert the Bruce (and his ploy to rule Scotland), his men used Robert's own dog, Donnchadh, to find him.

Though the animal led them to their target, he then turned and defended his master, who lived to become king of Scotland and produce a daughter who married into the Stuart family. Many generations later, the irrational actions of Robert the Bruce's direct descendant, King George III, would cause the American colonists to rebel.

Modern medicine attributes King George's apparent madness to porphyria, a genetically transmitted disease that researchers trace back to the Scottish Stuarts.