K9 is the name of several robotic dogs in the long-running British science fiction television series, Doctor Who. Although not originally intended to be a recurring character, K9 was kept in the show following his first appearance because he was popular with younger audiences. K9 has also been a central character in three of the series television spin-offs including K-9 and Company (1981) and K9 (2009-2010).

Dogs have three eyelids -- an upper lid, a lower lid and a third lid, called a nictitating membrane or "haw," which keeps the eye moist and protected.

The current record holder for world's oldest dog is Bluey, an Australian Cattle Dog who lived from 1910 to 1939 and died at the ripe old age of 29.

According to data from VPI pet insurance, the largest pet insurance company, Bella was the most popular dog name of 2013, probably due to the popularity of the Twilight series.

A dog's normal body temperature is between 101 and 102.5 degrees Fahrenheit.

a recent survey by the American Pet Products Manufacturers Association found that 42 percent of all dog owners allow their pets to sleep in the same bed with them at night.

In June 2005, Governor Rick Perry signed legislation adopting the Blue Lacy as "the official State Dog Breed of Texas". As expected, the vast majority of Lacy dogs are found in Texas.

Cynophobia is the fear of dogs. Ailurophobia is the fear of cats. Ornithophobia is the fear of birds. Anatidaephobia is the fear that a duck is constantly watching you.

Max is the Grinch's canine companion. He originally appeared in the book How the Grinch Stole Christmas, but has also been a prominent character in the television special, the film adaptation and the musical adaptation.

Dogs have about 1,700 taste buds. Humans have approximately 9,000, cats have around 473, and some species of catfish have as many as 180,000.