There is an entire cable TV channel designed especially for stay-at-home dogs, called DogTV. It costs $4.99 a month, as of 2015, and provides 8-hour blocks of programming, enough to entertain pets while their owners are at work.
DogTV was created with dogs in mind, taking into account everything from their colorblindness to their sense of hearing. While shows and videos made for people frequently contain sudden loud noises and vibrant colors across the entire visible color wheel for people, these things are startling for dogs who have much more sensitive hearing and are red/green colorblind. DogTV used scientific studies of the brains of dogs to determine their ideal soundtrack and designed it around canine sleep cycles to be alternately stimulating and relaxing. These studies also found that dogs can recognize other dogs on TV, and even respond differently to dogs of their own breed, although this is only on digital televisions, as analog televisions appear as flickering screens to dogs.
If you are unsure about how your dog would respond to this, or if you worry about the subscription fee, there are free sample episodes available on the official DogTV YouTube page. In the suggested videos, you can find many other examples of YouTube channels that create similar content for dogs. These include simulations of a trip to the dog park and walks on the beach, featuring other dogs.