Tapeworms in Dogs and Cats
Tapeworms are flat, white worms that are made up of tiny segments similar in appearance to grains of rice. They are often expelled from your pet's rectum alive in fresh feces, and you might see some that have been expelled onto their bedding or near their rear end.
How are pets infected with Tapeworm?
Pets get tapeworms by ingesting fleas infected with tapeworm larvae. When they reach your pet's intestine, they begin to mature and attach themselves to the walls of your pet's gut where they feed and grow. They can grow to be 4 to 8 inches long, but we usually only see the segments that separate from the adult worm and are shed out through the pet's rectum. These segments contain tapeworm eggs which are deposited into the environment where they are sometimes eaten by flea larvae. The larvae grow into adult fleas that hop onto your pet and start feeding. Your pet eats the flea while grooming or chewing a flea-bitten area and becomes infected with tapeworm.
How is Tapeworm treated?
If you report seeing rice-like worms on your pet or around their favorite nap spots, your doctor will recommend that you de-worm your pet and treat for fleas. Yes, it's possible that your pet just ingested one rogue flea and isn't dealing with an infestation but it's not likely. In Los Angeles we need to treat our pets for fleas every month, all year. Usually pets that have tapeworms also have fleas.
It's also possible that tapeworm won't be detected on an annual fecal parasite screen as the segments only shed intermittently. Because of this we don't run fecal samples that are suspicious for tapeworm to the lab. We prescribe a very safe de-wormer and flea medication based on your description of the worms. Usually one treatment or de-wormer is enough to eliminate Tapeworm as long as flea medication is used concurrently. Some doctors will prescribe a second dose several weeks after the first to protect against reinfection by other infected fleas in the environment, but it isn't strictly necessary as one treatment is effective in eliminating Tapeworm infection in your pet.