Common Types of Worms Found in Dog Poop

Child walking pug

As I took my Mastiff boy, Max, out on a bright and sunny morning as a part of our morning routine, his tail wagged energetically. Little did I know that our peaceful routine outing would soon lead me to find out something that I, like many pet owners, would rather not think about: the presence of worms in my dog’s poop.

Max paused by a patch of grass, a place he had visited countless times before. But this time, as he relieved himself, I noticed some tiny wriggling creatures in his poop. I realized that Max might be dealing with an issue I had heard about but never considered—worms.

In this article, we’ll delve into the common types of worms found in dog feces, how dogs get worms, how to identify them, and why timely detection and treatment are essential for your dog’s health.

Why Monitoring Your Dog’s Stool Is Important

A dog’s stool can reveal a lot about their health. From changes in color or consistency to the presence of worms or other anomalies, these signs may indicate underlying health issues that may need connecting with a vet.

Regularly inspecting your dog’s feces can help you catch problems early, ensuring your furry companion receives the necessary care. One common missed area is the presence of worms in dog poop.

Common Types of Worms in Dog Poop

1. Roundworms (Toxocara canis)

CC BY-SA 3.0

Roundworms are the most common intestinal parasites found in dogs. These spaghetti looking worms can grow up to several inches long and are often visible in feces or vomit. Puppies are susceptible to the roundworm infections, which can lead to poor growth and digestive problems.

Detecting roundworms in your dog’s poop can be irritating and unsettling, but it’s an important step in addressing the issue. However, what’s more concerning are the potential symptoms that may accompany roundworm infestation. These can include:

  • Diarrhea: Loose or bloody stools are common signs of roundworm infestation, often leading to discomfort and dehydration.
  • Potbelly Appearance: Some dogs with roundworms develop a distended abdomen, giving them a “potbelly” appearance.
  • Visible Worms: In severe cases, you may notice live roundworms in your dog’s stool, which is a clear indication of infestation.

If you suspect your dog has roundworms, consult your veterinarian immediately. Diagnosis is confirmed through fecal testing, and treatment involves deworming tailored to your dog’s needs. Follow your vet’s advice diligently to ensure complete removal.

2. Tapeworms (Dipylidium caninum)

By CDC’s Division of Parasitic Diseases (DPD)

Tapeworms are flat, segmented parasites that attach themselves to a dog’s intestines. They can appear in feces as small, rice-like segments or as whole worms. Dogs usually contract tapeworms by ingesting infected fleas or small rodents.

While the sight of tapeworm segments in your dog’s poop is a telltale sign of infestation, there are other indicators to watch for:

  • Weight Loss: Tapeworm infestations can lead to weight loss in dogs due to the parasites absorbing nutrients from their intestines.
  • Scooting: Dogs may scoot their rear ends across the ground as a response to the itching and irritation caused by tapeworm segments around the anus.
  • Irritation: Dogs may frequently lick or bite their hindquarters due to discomfort caused by tapeworm segments.

3. Hookworms (Ancylostoma and Uncinaria)

By DPDx Image Library

Hookworms are tiny, thread-like parasites that attach to the intestinal lining and feed on blood. You may not see adult hookworms in the stool, but signs of infection can include bloody diarrhea and anemia. Puppies can acquire hookworms through their mother’s milk or from contaminated soil. Other symptoms can provide valuable clues:

  • Dark or Bloody Diarrhea: Hookworms attach to the lining of the dog’s small intestine and feed on blood. This can lead to bloody diarrhea, which is often one of the first noticeable signs.
  • Anemia: Prolonged infestations can result in anemia, causing lethargy, weakness, and pale gums.
  • Weight Loss: Dogs with hookworms may experience weight loss due to the parasites sapping their nutrients.
  • Itching and Skin Irritation: In cases where larvae penetrate the skin, dogs may exhibit itching, redness, and discomfort.

4. Whipworms (Trichuris vulpis)

Creative Commons Attribution 4.0 International license.

Whipworms are long, slender parasites that reside in the cecum and colon. Whipworms are a type of intestinal parasite that can infest dogs, often without overtly revealing their presence. These elusive intruders are thread-like in appearance and inhabit the large intestine of their hosts, causing potential health issues that may go unnoticed until symptoms become apparent.

Unlike some other parasites, whipworms may not leave visible signs in your dog’s feces. However, specific symptoms can provide essential clues:

  • Chronic Diarrhea: Whipworm infestations often manifest as chronic, bloody diarrhea, which can lead to discomfort and dehydration.
  • Weight Loss: Prolonged infestations can result in weight loss due to the parasites absorbing nutrients from the dog’s intestines.
  • Abdominal Pain: Dogs with whipworms may experience abdominal pain, which can be exhibited through restlessness or discomfort.
  • Lethargy: General fatigue and lethargy can be indicative of whipworm infestation, as the parasites drain the dog’s energy.

5. Heartworms (Dirofilaria immitis)

   Cc: Heartworm Society

Unlike other worms, heartworms may or may not be visible in a dog’s feces. Heartworms reside in the heart and pulmonary arteries, making their presence largely invisible until more advanced stages of infestation. These worms are only detected through blood tests in most cases.

Understanding the life cycle of heartworms is crucial to grasp how dogs become infested:

  • Mosquitoes as Carriers: Heartworms require mosquitoes to complete their life cycle. When an infected dog is bitten by a mosquito, the mosquito ingests tiny heartworm larvae.
  • Inside the mosquito, the larvae develop into infective larvae over the course of about two weeks.
  • Transmission to Dogs: When an infected mosquito bites another dog, it injects these infective larvae into the dog’s bloodstream.
  • Over several months, the larvae mature into adult heartworms that reside in the heart and pulmonary arteries, causing damage and hindering blood flow.

While heartworms may not initially display obvious symptoms, infestations can progress to critical stages with notable signs:

  • Coughing: Dogs with heartworms may develop a persistent cough due to the obstruction of the pulmonary arteries.
  • Lethargy: Infested dogs may become lethargic, tired easily, and lose interest in activities they once enjoyed.
  • Weight Loss: Heartworm-infected dogs may experience weight loss and a reduced appetite.
  • Difficulty Breathing: As the infestation progresses, dogs may exhibit difficulty breathing, especially during physical activity.

Why Timely Detection and Treatment are Essential

Worm infestations can seriously deteriorate your dog’s health if the case is left unnoticed and untreated. Complications can include malnutrition, anemia, and in severe cases, organ damage or even death. 

Timely detection and treatment are essential for various reasons, including protecting your dog’s health, minimizing discomfort, preventing transmission to other animals and humans, avoiding complications, reducing treatment costs, and ensuring peace of mind. 

Regular veterinary care and prompt action when you suspect an infestation is the key to keeping your canine companion happy, healthy, and worm-free.

Discuss a deworming schedule with your vet based on your dog’s age, lifestyle, and geographic location. 

Also, practice good hygiene by picking up after your dog promptly to prevent the spread of parasitic eggs.


If you suspect your dog has worms or notice any unusual changes in their stool, consult your veterinarian for a proper diagnosis and treatment plan. Remember, a healthy pet is a happy pet, and keeping an eye on their stool is just one way to ensure their well-being.

Author Bio:

Nicole McCray is a die-hard animal lover who has worked in pet care for years. She is a former vet technician, a dog mom to her two rescue pups, and she grew up living and working at her family’s pet boarding facility. She loves using her writing talents to share the insight she’s learned throughout her career in the hopes that her knowledge can help other pet parents out there!

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