I wasn't actually in the show, but my two dogs were.

My mom works with animal castings for TV/movies and such, and was approached by a production company to provide dogs for their new reality show concept. The premise was that a family looking to adopt a dog would get 5+ dogs delivered to their house and live with them for a week. Afterwards, they'd pick which one they wanted to keep and adopt it.

Now, anyone who knows anything about dogs understands that this is a horrible idea and completely unfeasible to attempt for real, but that was the production company's intent. The families were not experienced dog owners and no shelter or serious dog owner would agree to lend their dogs to this dog-fight catastrophe waiting to happen. And my mom told the production company as such, to which they replied that they'd just fake it instead. So my mom rounded up a few dogs from friends and acquaintances that she knew were OK to be in a group together, and that included our two family dogs. They would then act as options for the families to "adopt" on the show, even though they all had loving homes and were in no way available for adoption. The families had in fact already adopted dogs before the filming even started, so adopting a dog from the show wasn't even an option. The dogs would then visit the family for a few hours each day for filming under strict supervision, and were never left alone with them as the show portrayed it.

Watching it on TV later was kind of surreal, knowing it was 100% fake. It was strange watching the families on the show discussing if they wanted to adopt my two dogs lying on the couch next to me while watching it.