How Do Fleas Turn Into Tapeworms?

Fleas and tapeworms are two different parasitic species. Fleas cannot turn into tapeworms. They do, however, play an important role in the incubation and transmission of tapeworm eggs. By acting as the vehicle for transmission, fleas can spread tapeworm infections to dogs, cats and humans. In addition, there are several species of tapeworm that are transmitted through rabbits and other mammals rather than through fleas.

Tapeworms

According to the Mar Vista Animal Medical Center, Dipylidium caninum is a kind of small tapeworm that usually reaches around 6 inches in length when it is full grown. The adult tapeworm hooks itself onto the intestinal wall of a dog or cat and extracts nutrients from the animal's body. Stanford University explains that the tapeworm's body is segmented into sections called proglottids. The proglottids contain eggs, and both the proglottid and egg are passed out of the dog's body through the feces.

Fleas

Larval fleas continue the cycle. As larvae, fleas gain nutrients from flea feces and small organic material. The larval fleas ingest the proglottids. The eggs hatch inside the larval flea's body to become tapeworm larvae. Mar Vista Animal Medical Center's website explains that the adult flea carries the tapeworm inside its body. When the flea bites a dog, the dog will sometimes bite at and swallow the flea. By swallowing the flea, the dog ingests the tapeworm. The tapeworm then grows to its full size inside the dog's intestine. The tapeworm is hermaphroditic (both male and female) and it continues the life cycle by releasing egg-filled proglottids through the anus.

Tapeworm Infections

Tapeworms can occasionally spread to humans, particularly children, through ingesting fleas or by an infected dog that licks the child's mouth. The Archives of Pathology & Laboratory Medicine Online indicates that people or animals that are infected with the Dipylidium caninum tapeworm will pass proglottids in their stool. They look like small, flat grains of rice.

Taenia Pisiformis

Taenia Pisiformis is another type of tapeworm. The Vet Info website explains that instead of using larval fleas, this kind of tapeworm is transmitted through rabbits. According to Washington University's Net Vet, the rabbit contracts the tapeworm by ingesting tapeworm eggs. The eggs hatch in the small intestine, and from there they are passed to the liver and peritoneal cavity. The dog needs to have physical contact with the rabbit to become infected.

Echinococcus Tapeworms

The Vet Info website indicates that Echinococcus tapeworms are transmitted through the livers and peritoneal cavities of small mammals like rats and mice, or through larger animals like goats or sheep. Dogs can be infected through direct contact with an infected animal.

References

• Mar Vista Animal Medical Center: The Common Tapeworm
• Stanford University: Parasites: Introduction
• Archives of Pathology & Laboratory Medicine Online: Infection by Dipylidium Caninum in an Infant
• Washington University's Division of Comparative Medicine's Net Vet: Internal Parasites of Rabbits
• Vet Info: The 3 Types of Dog Tapeworm

Resources

• DPDx Laboratory Identification of Parasites of Public Health Concern: Dipylidium Caninum Infection