Parasitic diseases

My Dog's Poop Has White Worms

Josie F. Turner
By Josie F. Turner, Journalist specialized in Animal Welfare. June 14, 2023
My Dog's Poop Has White Worms

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Seeing live worms in a dog's poop is the most comprehensive proof they have a worm infestation. You may see other symptoms before this happens since the dog may be experiencing serious gastrointestinal trouble, but it is also possible the concurrent symptoms are minimal. Regardless of the other symptoms, a worm infestation is a serious problem for the dog. This is especially the case due to the threat of parasite migration through the body. Eggs from the worms can travel through the body to the tissues of vital organs resulting in death of the animal.

At AnimalWised, we look at what happens when my dog's poop has white worms. We look at the types of worms which may be causing the infestation, as well as what treatment options we have available.


  1. Why does my dog's poop have white worms?
  2. What happens if my dog poops white worms?
  3. What to do if my dog's poop has white worms?

Why does my dog's poop have white worms?

Different types of intestinal parasites in dogs are the causes of white worms in their poop. These fall under two main categories which are roundworms (nematodes) and flatworms (cestodes). Typically, dogs parasitized by these worms eliminate eggs with their feces. It is unusual for them to expel adult parasites when defecating. However, there are species that do eliminate these parasites in their adult stage resulting in a dog's poop having white worms.


There are two species of nematode that parasitize the intestines of dogs and result in the elimination of adult worms. The main species associated with this symptom are:

  • Toxocara canis
  • Toxascaris leonina

Dogs can become infected with Toxocara canis in four different ways:

  • Direct ingestion: ingestion of embryonated eggs present in the environment.
  • Ingestion of paratenic hosts: the dog eats animals such as rodents, birds or invertebrates that have larvae infesting their tissues.
  • Transplacental route: infected mothers transmit the infection to their litter through the maternal-fetal circulation. In these cases, the puppies are born already parasitized.
  • Lactogenic route: in lactating puppies that ingest milk from infected mothers.

Toxascaris leonina can only be transmitted in two ways:

  • Direct ingestion
  • Ingestion of paratenic hosts

Regardless of the route of transmission, the adults of these parasites settle in the small intestine of the dog. They usually measure between 1.1-6" (3-15 cm) and they release eggs that are eliminated via the feces. In addition, it is common for the adult parasites themselves to be expelled periodically through the feces. It can also occur through vomiting, although this is not as common.

Learn more with our guide to roundworm infection in dogs.


Roundworms are not the only parasite which can result in white worms in the dog's poop. Cestodes of the genera Taenia and Dipylidium. These parasites are flatworms that are usually found in the intestine. Instead of causing the direct elimination of eggs in the feces, they eliminate segments of their body which are engorged with eggs. These segments are called proglottids , and in feces they appear like small worms, flattened, mobile, and whitish in color.

Although they appear like white worms in a dog's poop, they are actually egg-laden fragments of worms. The proglottids of these cestodes are easily differentiated from the adults of Toxocara and Toxascaris. The latter do not have a rounded body. Their bodies are flat and considerably smaller in size. If you see flat white worms in your dog's poop, about the size of a grain of rice, they are not live adult parasites, but part of them.

My Dog's Poop Has White Worms - Why does my dog's poop have white worms?

What happens if my dog poops white worms?

The presence of white worms in a dog's poop is a symptom that the parasitism has progressed significantly. The eggs have hatched, the larvae have developed and the adult worms have been egested. As stated in the introduction, it is possible there have been no other obvious concurrent symptoms. However, it is more common for the dog to present various clinical symptoms of parasitization.

When a dog is infested with worms, the ensuant disease is known as a parasitosis. There are two main issues when a dog is infested with any type of parasite, including white worms in their poop:

How worms affect the dog

The presence of these parasites in the animal's body can cause the appearance of various clinical signs. In adult and immunocompetent animals, symptoms associated with the infection may not be observed. In puppies and otherwise immunosuppressed dogs, the chances of symptoms presenting are much more likely. These include:

  • Developmental problems
  • Poor appearance
  • Bulging belly
  • Weight loss
  • Eye problems
  • Respiratory difficulties
  • Vomiting
  • Diarrhea

Gastrointestinal problems are a consequence of the presence of the parasite in the stomach and intestine. As we have previously mentioned, it is common for dogs to eliminate adult parasites with their feces or vomit.

In the specific case of Toxocara canis, the larval stages of the parasite can carry out lung migration. This is usually associated with the appearance of pneumonia, accompanied by coughing, nasal discharge and increased respiratory rate. In severe cases, the death of the parasitized animals may occur, both in the pulmonary migration phase and in the enteric or intestinal phase (due to intestinal rupture and peritonitis in dogs).

How worms in dogs affect others

This type of parasitism is highly relevant for public health, since they are a type of zoonosis. This means they are a disease in dogs that can be transferred to humans. Specifically, the larvae of the roundworm Toxocara canis can be transmitted to people and cause a disease known as visceral larva migrans (VLM). Although it can occur in people of any age, it is more common in children under five years of age, who are usually infected by ingesting soil contaminated with parasite eggs.

What to do if my dog's poop has white worms?

As we have seen in the previous section, the presence of worms in your dog's poop is of importance to the entire household and greater community. This is due to the potentially fatal health repercussions in the dog themselves and the potential for infection of people and other animals.

For the treatment of white worms in your dog's poop, you should follow the protocol we explain below:

  • Veterinarian: the first thing we need to do is go to our trusted veterinary center. They will carry out a stool test that will diagnose the parasitism and identify the specific species of parasite that is causing the infection. Based on this, a specific antiparasitic treatment should be established. This will be based on the correct parasiticide which will kill the species of white worm.

  • Hygiene: it is important to maintain a high degree of hygiene in the home to avoid transmission of the infection to other animals or people. It will also help prevent reinfection of affected animals. Heat (> 60 ºC/140 ºF), sodium hypochlorite (bleach), benzalkonium chloride or potassium hydroxide can be used as disinfectants for the animal's living spaces and accessories.

  • Contamination prevention: a series of measures must be taken to avoid contamination of the environment. In turn, this will prevent the transmission of the infection to people, especially children. Feces must be removed from the environment (parks, gardens, sandboxes, etc.), the access of dogs to children's play areas must be limited and the deworming schedule must be strictly followed.

Learn more about the importance of adhering to this schedule with our article on the importance of deworming a dog.

My Dog's Poop Has White Worms - What to do if my dog's poop has white worms?

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to My Dog's Poop Has White Worms, we recommend you visit our Parasitic diseases category.

  • European Scientific Counsel Companion Animal Parasites. (2021). Guide nº1. Control of worms in dogs and cats.
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My Dog's Poop Has White Worms