It could be a reference to two things:

In an early ep everyone thought Jan was allergic to Tiger a d co sidered giving him away. But it was the powder. So they may have given him away.

Or he died. The real dog on set died by getting hit by a car and they kept his dog house because a strobe light fell and it burned a hole in the astro turf. It covered it up. They reference it in the sequel where cousin Oliver chases him out into the street and you hear car breaks.