My cat has very thick, medium length fur. I didn't realize he was loaded with fleas, until I seen the tape worm. I researched and ask my vet about these white little worms. I found out they come from only from fleas. I bought this brand tape worm treatment, and flea meds. By the next day the worms where all gone and never came back. Now, I'm left with two pills. Hopefully my kitty won't need them again ;)