An examination was made as to the ability of Sentinel Flavor Tabs (milbemycin oxime/lufenuron) to treat Baylisascaris procyonis infections in dogs. The study was designed as a critical trial and included five naturally infected dogs and two dogs that were experimentally infected. Another dog from a prior clinical trial that was treated with Sentinel Flavor Tabs as part of the original FDA submission package for intestinal nematode infections was also included with the treated dogs. Of the five naturally infected dogs treated as part of the critical trial, three were cleared of their infections. These five dogs passed a total of 52 worms after treatment; one dog retained 23 worms and the other retained 1 worm at necropsy 7 days after treatment. Two of five experimentally infected Beagle dogs that had been given mice that had been fed 200 infectious eggs, developed patent infections with the parasite. These dogs were treated, and one of the dogs passed one worm and the other passed two worms after treatment with no worms being detected at necropsy 7 days after treatment. The one dog that was treated with milbemycin oxime as part of the FDA submission was clear of worms at necropsy. Overall, the mean efficacy of Sentinel Flavor Tabs was found to be 91.0%. Of the eight dogs that were treated, six were totally cleared of their infections, a cure rate of 75%. The two dogs that did not clear their infections had very large numbers of adult B. procyonis within their intestinal tracts at the time of treatment, one dog had 40 worms (23 remaining) and the other had 26 worms (1 remaining). It is suggested that the treatment of dogs with monthly Sentinel Flavor Tabs could markedly reduce the chance of infected dogs contaminating the environment. Also, additional monthly treatments are highly likely to clear dogs of any worms not killed with the initial treatment.