Symptoms of Intestinal Parasites in Dogs

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Intestinal parasites in dogs is an example of how something little can lead to a big problem. Your pet may display no symptoms — what veterinarians refer to as subclinical — so exercise due diligence by scheduling regular veterinary exams and preventive care. If there are changes in your dog's appearance, eating habits, or stool, schedule an exam with your veterinarian to determine if they have an intestinal parasite.


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What are intestinal parasites?

Intestinal parasites are organisms that live in your dog's intestinal tract.‌ By being in this location, they're able to consume nutrients at your dog's expense. Some intestinal parasites are worms, such as roundworms, tapeworms, and hookworms, while others are microscopic protozoa, such as Giardia or Coccidia. Any dog is susceptible to picking up intestinal parasites.


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Causes of intestinal parasites in dogs

Dogs usually pick up intestinal parasites in a variety of different ways, such as ingesting dog feces containing an immature state of a worm, called larva, or even picking up certain parasites from the mother dog while nursing as a puppy. Some of the most common intestinal parasites in dogs include:


  • Roundworms:‌ Dogs can contract this parasite while in their mother's womb, from their mother's milk, or from ingesting larvae, such as those in contaminated soil.
  • Hookworms:‌ This parasite is unique because in addition to ingestion, dogs can also pick them up through the skin or through their mother's milk.
  • Tapeworms:‌ Dogs usually pick up tapeworms when they ingest an infected flea that is infected with tapeworm larvae.
  • Whipworms:‌ A dog can become infected with this parasite if they ingest something like stool or soil that contains whipworm eggs.
  • Coccidia:‌ Your dog can ingest the immature stage of this parasite in contaminated soil or feces. This parasite is more common in puppies and less common in adult dogs.
  • Giardia:‌ This parasite can be picked up by ingesting contaminated water, soil, or stool.


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Symptoms of intestinal parasites in dogs

Any negative change in your dog's general health or the development of gastrointestinal signs should raise a red flag for you.


  • Diarrhea:‌ Roundworms, hookworms, tapeworms, whipworms, Coccidia, Giardia. These parasites can sometimes cause bloody diarrhea. With hookworms, the stool might be tarry, and a dog can develop life-threatening anemia due to blood loss. Giardia can cause watery diarrhea.
  • Vomiting:‌ Roundworms, hookworms, Coccidia, Giardia. Dogs with a heavy roundworm infection may vomit worms.
  • Weight loss:‌ Roundworms, hookworms, tapeworms, whipworms, Coccidia, Giardia. Infected dogs can also experience changes in appetite.
  • Poor coat condition:‌ Roundworms and tapeworms
  • Pot-bellied appearance:‌ Roundworms
  • Lethargy:‌ Roundworms, hookworms, tapeworms, whipworms, Coccidia, Giardia
  • Anal itching:‌ Roundworms, hookworms, tapeworms, whipworms, Coccidia



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Diagnosing intestinal parasites in dogs

An at-home diagnosis of intestinal parasites is difficult because you usually won't see the worms. One exception is the unlikely event that your dog vomits up worms, which indicates a severe infection. The other exception is with tapeworms, as you might see segments of the worm that break off from the body and are passed in the stool. They look like grains of rice in or on the stool and/or around the anus.


To diagnose intestinal parasites, your veterinarian will need a fresh stool sample to perform fecal tests and possibly bloodwork to diagnose any associated problem. Testing also enables your veterinarian to identify the proper treatment. If you do detect clear evidence of parasites, don't try to treat your dog yourself. Your pet could potentially have more than one parasite infection (not unusual in puppies) and may require more than one medication.


How to treat intestinal parasites in dogs

Depending on the parasite, your pet will receive one or more medications. If your dog has complications from having an intestinal parasite, like dehydration due to vomiting or diarrhea, they might also receive IV or subcutaneous (under the skin) fluid therapy.

You should also pay attention to the following:

  • Yard:‌ Keep the yard picked up of your dog's stool every day to help reduce the likelihood of reinfection. However, with a parasite like whipworms, whose eggs can survive in the ground for up to five years, it's nearly impossible to eradicate them from a yard once the ground has been contaminated.
  • Pet supplies:‌ Wash your dog's toys, food, and water bowls daily. Also wash their bedding and kennel at least weekly during treatment.
  • Bathing:‌ For parasites like Giardia, it's also recommended to wash the dog's hind end on the last day of treatment to remove any parasites or their cysts. Be sure to use gloves because the parasite has zoonotic potential. However, most human cases of Giardia are a different species of the parasite and not the species that dogs can carry.


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How to prevent intestinal parasites in dogs

It's not difficult to employ basic preventive measures to help keep your dog parasite-free.

  • Veterinary advice:‌ Follow your veterinarian's advice on treatment of infected animals, routine deworming treatments, and/or monthly heartworm preventatives (which also contain dewormer), obtained through them or purchased over the counter if applicable.
  • Flea control:‌ Develop a flea-control plan with your veterinarian to prevent a tapeworm infestation. Pets in certain climates will need year-round flea prevention.
  • Potty area:Keep your dog's potty area clean and try to keep your dog away from areas that may have contaminated feces left by other dogs.

The bottom line

Any dog can pick up intestinal worms and other internal parasites, like Giardia or Coccidia. Parasites are often picked up when a dog ingests something that's contaminated with parasite eggs, cysts, or larvae. But some parasites, like roundworms and hookworms, can even be passed to a puppy through their mother's milk. Intestinal parasites in dogs can cause a variety of symptoms, such as vomiting, diarrhea, or lethargy. A hookworm infection can cause additional health problems, like blood loss. If you observe changes in your dog's appearance, appetite, or bowel habits, schedule an appointment with their veterinarian for proper diagnosis and treatment.



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