As a pet parent, you may be shocked to find worms in dog poop — but you're not alone. Intestinal parasites including hookworms, roundworms, whipworms and tapeworms are common in dogs. Worms can often cause a variety of health concerns and they're highly contagious. Moreover, these parasites can easily go undetected unless you take your dog in for routine checkups and ask your veterinarian to look for microscopic worm eggs in their dog poop. If you want to learn more about keeping your dog free of worms, keep reading to learn more about how to spot worms in your dog's feces and how they may affect your dog's health.

How Do Worms Affect Your Dog and Their Health?

Your dog's health, size and age will play a large role in how intestinal worms will affect their overall health. The type and number of worms a dog is infected with are also influential. Worms not only live in the stomach and intestines, but they can also be found in the heart, kidneys, lungs and other organs. Keep in mind that ringworm, which is also seen in dogs, isn't actually a worm but a fungus.

Dogs can contract intestinal worms in several ways. A mother dog can pass worms to her puppies in the womb or when nursing. Dogs can also become infected with worms by ingesting dog poop that contains worm eggs or eating another animals poop that's infected with worms. Dogs can become infected with tapeworms if they ingest a flea that contains tapeworm larvae. Worms are obligate parasites that get all of their nutrition from their host. Dogs who are smaller, younger and/or have a compromised immune system may be more prone to developing worms in their poop than others.

What kinds of worms commonly affect dogs?

The four main worms found in dog poop are hookworms, whipworms, roundworms and tapeworms.

  • Hookworms are tiny, thin worms with hook-like mouth parts.
  • Whipworms look like tiny pieces of thread that are enlarged on one end.
  • Roundworms look like spaghetti and may be several inches long.
  • Tapeworms look like grains of rice

The best way to identify worms in dog poop is to take any worms you find along with a sample of your dog's poop to your veterinarian, who will help you identify and treat any parasites. Most of the time you won't see adult worms, so they're usually diagnosed by a veterinary professional with a fecal float test. The poop sample is dissolved in a special solution and spun in a centrifuge to be examined under a microscope to look for worm eggs in dog poop.

How Are Intestinal Worms Treated?

Fortunately, worms in dog poop are usually easily treated. Depending on the type of worm(s) that your dog has, your veterinarian will prescribe a dewormer that will kill any adult worms your dog is harboring. Dewormers that may be prescribed can include fenbendazole, milbemycin, praziquantel, moxidectin or pyrantel pamoate, and they come in many forms, including liquid medication, injections, tablets, topical forms or chew forms. Dewormers require only one or a few doses, making them safe, effective, inexpensive and easy. If you notice that your dog passes worms after being dewormed, either in the stool or vomiting, that means that the dewormer is doing its job.

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We believe that science is the best path to giving your pet the best care possible. 

How Can You Prevent Worms?

Once your dog is worm-free, be sure to talk to your veterinarian about monthly worm prevention. Many monthly heartworm prevention medications include intestinal parasite prevention medication as well, making total worm prevention easy. These medications work by killing any intestinal parasites that your dog is exposed to. For these medications to work properly, give them to your dog as directed.

In addition to giving your dog a monthly broad-spectrum worm prevention medication, it's also recommended that you have your dog's stool checked every 6 to 12 months for microscopic parasite eggs. No medication works 100% of the time, so having your dog's poop checked regularly will ensure that the monthly prevention is doing its job of keeping worms out of your dog and out of your life.

Dr. Sarah Wooten Dr. Sarah Wooten

Dr. Sarah Wooten graduated from UC Davis School of Veterinary Medicine in 2002. A member of the American Society of Veterinary Journalists, Dr. Wooten divides her professional time between small animal practice in Greeley, Colorado, public speaking on associate issues, leadership, and client communication, and writing. She enjoys camping with her family, skiing, SCUBA, and participating in triathlons.