Someone breeds them then can't take care of them. These three guys and one girl (the tri-colour one) are all available. I'll let the pictures and video do the talking.
The best way to check on the adoption status of these pups (and other dogs and cats and other small domestic animals) is to visit Toronto Animal Services adoption website or call 416 338 6668 for the Toronto Animal Services South shelter. If the pups are no longer on the TAS adoption website, it's probably because they've been adopted already.