I agree but panacur is pretty darn safe. I am a vet tech so have no issues with self medicating my pets. I can see no reason why feeding a rat with meds would affect the meds effectiveness but I thought I should put it out there cause "ya never know" I can run a float myself but since I deworm everything else on a regular basis I usually do not bother with the fecals unless something is really wrong an an exact diagnosis is required. Most do not realize that routine fecals are one way a DVM can make 100% profit. It is a money maker and costs more than the wormer itself. Panacur is one of those in and out meds (no residual), it only affects worms in the gut not the pet.