Even More Dog Facts You Didn't Know

1. In Russia, some dogs are known to use the subway to travel to more populated areas in search of food
2.  A 2009 study by New York professor Alexandra Horowitz found that the 'guilty dog look' owners know so well is usually triggered by the dog being scolded by its owner - and is not related to whether the dog has actually misbehaved or not
3.  Currently, there are 339 recognised dog breeds, according to the World Canine Organisation.
4.  Measuring a mere four inches (10 cm) in height, Boo Boo, a Chihuahua, was declared the world’s smallest dog by the Guinness World Records in 2010.
5.  Owing to a special membrane, called the tapetum lucidum, dogs are able to see in the dark.
6.  Chihuahuas derive their name from the state in Mexico where they were discovered.
7.  The Holy Bible mentions dogs 14 times.
8.  Dogs curl up while sleeping to protect their vital organs and abdomen from predators.
9.  A bounty of US $300,000 was put on the head of US Customs' dogs, Rocky and Barco, by the drug cartel, because of the canine duo's efficiency in patrolling the Mexican border. 
10. Laika became the first dog to be sent into space via a Soviet satellite in 1957.