You Make The Diagnosis: Name This Fecal Parasite Found in Dogs

Pictured below is a worm that was found crawling on the fur around the anus of a dog. The owner also found more of the worms on the dog’s stool. Study the picture of this flat, off-white colored worm and then answer the following questions: 1) What is the name of this parasite? 2) How is it differentiated from maggots? 3) How are animals infected?


Diagnosis: Tapeworm Taenia pisiformis and Dipylidium caninum are the most common types in dogs.

The worm or parasite in the picture is a tapeworm segment.  Unfortunately, no eggs were found during fecal analysis to determine the exact species. The segments of tapeworms are flat whereas maggots are round. Dried segments look like grains of rice. Tapeworms are made up of a head and neck followed by segments that make up the rest of the body. Each segment absorbs nutrients from the small intestine of the host. Segments at the end of the worm, break off and are discarded in the feces. Fleas eat the segments releasing the eggs inside. Dogs and cats are infected when they eat fleas.


-Rothrock, Kari. ‘Tapeworm Infestation’ Associate Database, VIN last updated 10/31/2012.

Published by kristennelsondvm

Dr. Kristen Nelson grew up on a farm in Watertown, Minn., where she developed a deep love for animals of all kinds. She received a Doctor of Veterinary Medicine degree from the University of Minnesota, College of Veterinary Medicine. Kris then completed a small-animal internship at the prestigious Animal Medical Center in New York City. In addition to writing and speaking, she cares for small and exotic animals in Scottsdale, Az. Dr. Nelson is widely quoted in the media. Her credits include Ladies’ Home Journal, USA TODAY, the Los Angeles Times and numerous radio and television interviews. Dr. Nelson has written two books, Coated With Fur: A Vet’s Life and Coated With Fur: A Blind Cat’s Love. Kris and her husband Steve share their home with rescued cats, birds and a dog.