Technology is beginning to play a big role in the way pet owners care for their pets. Among the new offerings in the $50 billion annual market: San Francisco's own Whistle raised $6 million in June for its $100 Fitbit-like activity tracker device for canines, which monitors dogs' sleep and exercise patterns; Rover.com, an online alternative to traditional dog boarding; and Halo Belt, a company that makes illuminated pet collars, launched via Kickstarter.