Almost 40-percent of us own dogs. But how much do we really know about them? Hereís a True/False test to find out: 

  • First, True or False: Dogs are extraordinary service animals. Thatís True. We all know about Seeing Eye dogs, but get this: Dogs can sniff out the faint odors given off by cancer cells. They can also smell differences in blood sugar levels before their owner feels any symptoms of diabetic shock. And no oneís sure why, but some dogs can predict an epileptic seizure 45 minutes before it starts.

  • The next canine True/False question: Dogs are as smart as 2-year-old children. Well, that depends on the breed. Canine expert Stanley Coren says that Border Collies can understand as many words as a 2-year-old. Other dogs that rank high in the smarts department include Poodles, Dobermans, German Shepherds, and Golden Retrievers. But older breeds - like Hound dogs, Beagles, and Bulldogs - were bred to recognize things by sight or smell, so vocabulary isnít their strong suit.

  • Question #3: Dog years are different for different breeds. Thatís True. According to The American Naturalist, breeds that are considered obedient and easy to train outlive their more-aggressive counterparts. Thatís because they expend less energy overall, so, thereís less wear-and-tear on their bodies. So, itís not unusual for a Poodle to live 15 years, while a 7-year-old Bulldog is considered a senior citizen. Also, larger dogs age faster than smaller breeds. So a Great Dane may only live 8 years, while a Chihuahuaís lifespan can be 15 years.