Proglottids are the
flat,
rectangular segments that grow from a
tapeworm's
anterior. These segments develop both male and female sex organs, so although the segments share muscular structure and a
crude nervous system with the tapeworm, each proglottid can be can be consider a separate sexually-reproducing individual.
A 5 meter long Taenia saginata (beef tapeworm) may contain thousands of proglottids , which, as they become gravid, detach and migrate to the anus or pass to the stool. These proglottids contain anywhere from 80,000 to 100,000 eggs which can survive for months or years in water, or the soil, waiting to be picked up by another host.
How to tell if your
pet has a tapeworm:
Proglottids may break off from the adult tapeworm and are passed in the
feces. Do you see any cream colored things about the size of a
grain of rice attached to the
fur around the your pet's
anus? They're probably not
cucumber seeds.
Is your pet
scooting around the floor? The proglottids of
Dipylidium caninum are very
mobile and
crawl around your pet's anus, making it
itch.
By the way, in case you're wondering about your own digestive tract-- most tapeworm infested patients do not know they are infected until they discover a single proglottid crawling out of their anus or individual proglottids
are spotted on the surface of their stool.