Common Dog Worms

By Janice Jones     |Last Updated 07-06-2021

Discussing those common dog worms that live in the intestines and hearts of dogs does not make for polite dinner conversation.  However, if left unchecked, these little creatures can make your dog and even you very ill and could be potentially deadly. 

The most common types of intestinal worms include roundworms, hookworms, whipworms, and tapeworms. 

Dogs can also acquire Coccidia and Giardia, which are single celled organisms.

Click here to learn more about Coccidia.

In addition to those dog worms that live in the intestinal tract is the heartworm


round worm on blue backgroundRound Worm

The most common form of intestinal parasite is the roundworm.  Animals with roundworms pass the infection to others when they shed the worm’s eggs in their stool. 

Other animals will eat the infected feces, walk on it and lick their paw, or drink contaminated water. 

Mothers can pass the infections onto their puppies either before birth or during nursing.  Infected animals can have serious health problems including malnutrition and intestinal issues including diarrhea. 

Infected animals pose a risk to people because the eggs can be accidentally eaten or enter through the skin.  Children are at greatest risk especially if they play in areas with infected feces. 

If untreated in people, the larval forms can eventually enter organs and other tissues resulting in damage.


microscopic hook worm eggHookworm egg as seen under a microscope

Hookworms are also common in dogs and can be especially dangerous because they bite into the intestinal lining of the dog and suck blood. 

If untreated, hookworm infestations can result in potentially life threatening blood loss, weakness, and malnutrition.  Sadly, humans can also be affected when larvae penetrate the skin. 

If hookworm larvae penetrate the skin they can cause "cutaneous larval migrans", a potentially serious and scarring inflammation results.   

The larvae produce severe itching and tunnel-like red areas as they pass through the skin. Symptoms that the dog may show include bloody diarrhea, weight loss, anemia, and progressive weakness.


microscopic whip worm eggWhipworm egg as seen under a microscope

Whipworms pass their eggs in the feces and other animals become infected by eating infected soil or licking areas of their bodies that have come into contact with the whipworm eggs. They are very resistant and can live in the environment for 5 to 7 years.  

Whipworms are similar to hookworms in so far as they bury their heads into the lining of the dog’s intestine and such blood, but are not as harmful as the hookworm. 

The Whipworm lives in the first section of the dog’s large intestine called the cecum and are often more difficult to detect because they shed few eggs.  Some of the symptoms that a dog with whipworms may display include chronic weight loss, and feces that seems to have a  lightring of mucus. 

Whipworms rarely infect humans.  Whipworm infection is detected by viewing the eggs under a microscope.  It sometimes takes several samples for eggs to be seen as they do not shed many eggs at one time.


segmented tape wormTapeworm is seen by the naked eye.

Tapeworms are the only worm you can actually detect without the aid of a microscope.  They are thin flat-segmented worms that are passed from animal to animal when the dog eats infected fleas or lice. 

They can also get certain types of tapeworms by eating infected rodents.  The dog will pass segments of the worm that can be detected under the tail or in the stool.  They look like flattened grains of white rice.

These visible portions are only a segment of the actual worm and contain the eggs.  They will be moving if they are still alive.  If they are dead, they appear as yellowish-gold rice segments.

Do not mistake the tapeworm for maggots.  Maggots are rounded and are not seen in freshly passed stool.The full worm is much longer.  People do not generally get dog tapeworms.

Risk Factors for Common Dog Worms

Four scenarios put dogs at risk for worms: 

  • Newborn Puppies:    Roundworm eggs can form cysts in adult dogs and that remain dormant.  When a female dog is pregnant, these dormant eggs will activate and infect the puppies.  The mother's milk can also pass roundworms to puppies.

  • Contact with infected dirt - Roundworm eggs and hookworm larvae can reside in dirt.  If you dog runs into infected dirt while on a walk, at a dog park, or out in the wild, your dog may get worms.

  • Fleas - Young tapeworms can reside in fleas.  If your dog swallows fleas while licking a paw or other part of his body, he could ingest tapeworms and be infected.

  • Hunting or eating wildlife - wild animals may carry worms, including tapeworms residing in fleas on wild animals.  If your dog hunts or eats wildlife, your dog may swallow worms.

Diagnosis of Common Dog Worms

A veterinarian can perform a simple fecal test and prescribe a de-wormer. You will need to take a fresh fecal sample to your veterinarian to have the test performed. 

At the vet's office, a technician will mix the sample with a special medium and then prepare a slide.  Worm eggs can be detected under low power magnification.

Treatment for Common Dog Worms

There are a few medications on the market today that will take care of the parasites in inhabit your dog.

To treat the coccidia organisms, veterinarians will use drugs  such as sulfadimethoxine (Albon®) and trimethoprim-sulfadiazine (Tribrissen®)

Heartgard Plus**Tri-Heart Plus**Iverhart Plus** is used to treat Heartworms, but it also takes care of as well as preventing Heartworm.  Their main ingredients are ivermectin and pyrantel pamoate.

Drugs such as Nemex-2** contain pyrantel pamoate and treat roundworms and hookworms.  Drugs such as Panacur** and Safegard** are used to treat roundworms, hookworms, whipworms and tapeworms. If given for a longer period of time, they will also treat coccidia.

Prevention of Common Dog Worms

  • Keeping fleas away from the dog will also prevent tapeworm infections. 

  • Do not let your dog roam and hunt; raw meat, carrion, or parts of dead animals that are likely carriers of parasites.

  • Keep your grass mowed and pick up feces frequently.

  • Keep up to date with monthly heartworm medication

To protect yourself and your family the best preventative is good hygiene, which means:

  • Wash hands frequently
  • Keep sandboxes covered
  • Wear shoes when outdoors.

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The images used on this page are courtesy of Creative Commons

About Janice

Janice is the voice behind Miracle Shih Tzu. Having lived with dogs and cats most of her life, she served as a veterinary technician for ten years in Maryland and twelve years as a Shih Tzu dog breeder in Ohio.

Her education includes undergraduate degrees in Psychology with a minor in biology, Early Childhood Education, and Nursing, and a master's in Mental Health Counseling.

She is a lifelong learner, a dog lover, and passionate about the welfare of animals. Her favorite breed for over 50 years has been the Shih Tzu.

When not writing, reading, or researching dog-related topics, she likes to spend time with her eight Shih Tzu dogs, her husband, and her family, as well as knitting and crocheting. She is also the voice behind Small Dog Place and Smart-Knit-Crocheting.