I've since gotten a few emails about the advert, so here it is (with my thanks to everyone who emailed):
Video Description: A series of video clips of dogs set to Tony Rogers' song "Great."
The lyrics used in the advert are: To a point I was good / Tried to do stuff that I should / Tried to do what you said / Tried to sleep in my own bed / But my bones wouldn't rest / 'Til I put me to my test / And I remembered what you said / I could be great / So so great...
The clips are, in order (having made a good-faith effort with breed identification, I dearly hope this thread does not turn into a pedantic nitpicking session about my description): A brown shepherd-mix wagging its tail and grinning; a black and white Boston Terrier sitting on a couch like people; a black and white Chihuahua walking across the back of a couch; a grey and cream Husky (or maybe Malamute) puppy laying half in a water bowl; a tan and silver Yorkie perking up its ears; a red Shiba Inu playing with a ball; a white Maltese puppy in a pink bed; a fawn and white English Bulldog sleeping on its back; a golden-mix pawing at a Frisbee (I think) on a hardwood floor; another Yorkie cuddling up for a nap; a black and tan Dachshund-mix looking out a window; a black Scottish terrier retrieving a ball from the water; a tan terrier-mix leaping through the snow; a black and white and silver Australian Shepherd running in the grass; a lab-mix long-distance diving at a competition; a black and white Border Collie catching a Frisbee; a red and white terrier-mix leaping a fence; a white Labradoodle play-bows in the grass; a Vizsla puppy runs with floppy ears; a brown and white English Bulldog on a surfboard; a black shepherd-mix in a wheelchair goes for a walk; a black Newfoundland rescue dog jumps out of a helicopter into the ocean; a black and tan German Shepherd search and rescue dog walks through building wreckage; a yellow Lab search and rescue dog digs through snow; a white Silken Windhound therapy dog stands calmly being pet by an older woman; a Yorkie lies beside a man in a hospital or hospice bed; a black Lab guide dog walks with its person down the street; a yellow Lab high-fives its owner in an agility competition; a Husky welcomes home a servicemember by enthusiastically licking his face. Text onscreen: Inside every good dog is a great dog.
[Note: Even though this is an advert for a specific dog food, posting the ad is not an endorsement of Purina, and, in fact, I do not use Purina dog food. Please note that discussions of Purina's corporate practices and advocacy for specific pet diets, while worthy discussions, are off-topic for this thread.]