About 3 hours ago I treated my boy Frankie with Profender, a topical de wormer prescribed by the vet. Frankie's stool sample came back positive for round worms. All I want to know is how soon will he start expelling the worms? This is my first time doing this and I don't know when he will start passing them. I was kinda expecting the medicine to start working by now. Should I be concerned? My vet spoke of the possibility of intestinal blockage if all the worms died at once and that for the next 12-24 hours I need to watch him. I am a very over protective mama with Frankie and I am over here waiting for him to use the bath room so I can check his feces and remove it from his litter. Please someone settle me down. I need to know what to expect.