Pet Threat: Yes | Human Threat: Only if you eat fleas
Parasite Profile
As though fleas weren't bad enough themselves, they are also the primary carrier for another type of parasite: the tapeworm. Tapeworms are fairly innocuous; they are not nearly as dangerous, for example, as heartworms, hookworms or roundworms. Though they can be transmitted by other means, tapeworms primarily enter a dog directly through the ingestion of a flea, which serves as a parasitic Trojan Horse.
Targets
Given their attractiveness to fleas, dogs are primary targets of tapeworms. An infection starts when a flea larva consumes a tapeworm egg, usually in an infected dog's bedding. (You'll find out why in a minute.) The flea larva matures into a flea with the tapeworm larvae inside. The dog then ingests the flea during the course of grooming. Once the ingested flea is digested, the tapeworm is free to hatch and attach within the dog.
Clinical Signs
Tapeworms, which can reach up to 13-27 inches in length, grow in segments. The end segments, which contain new eggs, break off as the worm grows, and pass out through the rectum of the dog (which is why they are sometimes found in bedding). Tapeworm eggs are sometimes visible in an infected animal's feces, bedding or in the matted hair around the anus.
Treatment
A veterinarian can provide a dewormer. Some veterinarians recommend two deworming sessions based on the assumption that clearing the flea problem that caused the tapeworm issue may take some time.
Prevention
To help prevent tapeworms, be sure to use a flea preventive that kills adult fleas, flea eggs and especially flea larvae.