How to Tell If Your Dog Has Worms

Leslie Gillette, DVM
By Leslie Gillette, DVM on Jun. 30, 2020

One of the most common concerns that you may face as a dog owner is whether or not your dog has worms. As gross as that thought may be, intestinal worms are pretty common. 

Here’s what you need to know about worms in dogs: how to tell if your dog has worms, how dogs get worms, and how to get rid of worms in dogs.

How Do Dogs Get Worms?

Here are some of the most common ways that dogs get worms:

Eating Feces

Transmission of intestinal worms (hookworms, roundworms, and whipworms) commonly occurs when your dog ingests contaminated soil or feces containing eggs or immature worms (larvae) that have been passed from other infected animals in the environment.  

Roundworm infections can develop when the ingested eggs hatch and the larvae migrate through the tissues of other organs, often a dog’s lungs and liver, before returning to the small intestine to grow to maturity. Whipworms typically grow to maturity in the upper part of the large intestine.

Getting Them From Their Mother

Pregnant and nursing dogs can transmit hookworm and roundworm larvae to their puppies during pregnancy if the larvae migrate across the placenta. These larvae can also migrate into the mammary glands and be passed to puppies during lactation. Hookworms, like roundworms, will eventually grow to maturity in your dog’s small intestine.

Ingesting Fleas While Grooming

Your dog could be infected with tapeworms while licking herself during grooming, or by chewing at her fur. Fleas transmit tapeworms by ingesting the tapeworm egg packets in the environment before jumping on your dog for a blood meal. Once the flea host has been swallowed and digested, the tapeworm larva is able to attach to the wall of your dog’s intestine and grow to adulthood. 

How to Tell If Your Dog Has Worms

Since worm infestations can sometimes show few to no symptoms, keep an eye out for any or all of these changes in your dog’s daily health and appearance:

  • Diarrhea, sometimes containing blood or mucus

  • Vomiting, which can sometimes contain adult worms

  • Weight loss, particularly if your dog has a good appetite

  • A bloated belly or generally “unhealthy” appearance

  • A dull, dry coat

  • Excessive scooting and chewing at their bottom

  • Visible segments that look like grains of rice attached to the fur around their bottom or on their tail (or in their feces)

Common Types of Worms and Their Symptoms

Here’s a list of common types of worms in dogs and the specific symptoms you might see for each.


Adult whipworms are smaller than roundworms and may be visible to the naked eye, but they are uncommonly seen as adults in the feces. These worms can cause:

  • Chronic weight loss

  • Bloody diarrhea and/or a visible mucus coating on the feces when passed


Adult hookworms are usually not visible to the naked eye. Hookworms could cause:

  • Bloody diarrhea

  • Anemia

  • Weakness

  • Lethargy 


Roundworms are visible to the naked eye (they look like spaghetti) and can be seen in feces or sometimes vomited or coughed up as single worms or in clusters. They can cause:

  • Diarrhea

  • Weight loss

  • Lethargy

  • A ”potbellied" appearance

  • A dull coat


Tapeworms can look like grains of rice on your dog’s fur (individual egg packets) or may be visible to the naked eye in longer segments. They can cause:

  • Excessive scooting

  • Itching

  • Chewing at the rear end

Can Humans Get Worms From Dogs?

Humans can also contract hookworm and roundworm infections if they accidentally ingest contaminated soil or feces. Frequent hand washing and wearing shoes and appropriate clothing outdoors can decrease the chance of exposure.


Humans can be exposed through dogs, usually by coming into contact with their contaminated waste. Theoretically, it may be possible to contract roundworms by petting a dog, if the dog had recently rolled outside in the dirt and picked up either contaminated soil or fecal material on their fur.

Roundworm ingestion can sometimes lead to a condition called “visceral larval migrans,” which occurs when the roundworm larvae migrate through the intestinal wall into other internal organs, including the lungs, heart, nervous system and eyes. Roundworm larvae have been identified in several cases of acute blindness and retinal detachment in humans.


People can get hookworms by walking barefoot, although there have been cases of people developing lesions on their back or shoulders after lying on the ground with no shirt on. Any exposure of bare skin to contaminated soil/feces could pose a risk for transmission.

Exposure to soil that is contaminated with hookworm larvae can lead to a skin condition known as “cutaneous larval migrans.” These infections look like red tracks or coiled lesions just below the surface of the skin and can cause a great deal of itchiness as the live larvae migrate through the tissue.

It is rare, but hookworm larvae can also survive in the intestine and grow to adulthood in a human host, which can cause intermittent and recurrent episodes of abdominal pain and cramping.


Tapeworms can be passed to humans much like they are transmitted in dogs—by ingesting an infected flea. Once the flea is swallowed and absorbed in the digestive tract, the tapeworm larva can attach to the wall of the intestine.


Canine whipworm infections are species-specific and not typically considered a zoonotic threat to humans.

How to Get Rid of Worms in Dogs

Here’s what to do if you suspect that your dog has any type of intestinal parasites.

Call for a Vet Appointment

If you think your dog might have worms, you should schedule an appointment with your regular veterinarian right away.

If left untreated, intestinal parasites can migrate to other organs in your dog’s body, including the heart, lungs, liver, eyes and brain, which could lead to worsening sickness and even death in the most severe cases.

Collect a Sample of Your Dog’s Stool

Your veterinarian may ask you to bring a fresh sample of your dog’s stool from home, especially if you are seeing worms in their feces or notice dried, rice-like segments in their fur.

You only need a small amount of feces; usually about a teaspoon-size sample will do.

If you cannot collect a fresh sample at home, however, the veterinary staff will collect a sample when you arrive for your dog’s appointment.

If your vet is suspicious of hookworms, roundworms, or whipworms, they will be looking for individual microscopic eggs in the sample.

Tapeworms can be identified microscopically by their egg packets, which are the rice-like segments you might also see attached to your pet’s fur. Occasionally, you may also see an adult worm in the fecal sample, which can be extremely helpful for identification.

Use Deworming Medications Prescribed by Your Vet

Once your veterinarian has had a chance to examine your dog and analyze the fecal sample, they will determine the best type of deworming medications to treat the worms that are present.

Your veterinarian may prescribe an oral or injectable dewormer that will kill the adult and larval worms. They may also recommend starting your dog on monthly topical or oral flea prevention, since tapeworm infections can recur if there are fleas in your dog’s environment.

Oral Dewormers

“Broad spectrum” prescription medications such as Panacur (fenbendazole) and Drontal Plus (pyrantel, praziquantel, fenbendazole) can be used to treat hookworm, roundworm, whipworm, and tapeworm infections, but they must be carefully administered according to your veterinarian’s instructions and may require multiple doses to kill any larvae that may have hatched after the first dose was given.

Oral dewormers do not generally cause severe side effects. If your dog has a large worm burden at the time of treatment, it is possible that an oral dewormer could cause mild diarrhea, vomiting, and a temporary loss of appetite as the worms are paralyzed or killed by the medication and passed from your dog’s system. 

Injectable Dewormer

Praziquantel is also available as a one-time injectable treatment for tapeworm infections, which works by paralyzing and dislodging the sucker of the worm from the intestinal wall, allowing the worms to be passed in the feces. 

Injectable dewormers may cause a local injection site reaction, including pain, swelling, and local inflammation due to its viscous nature.

Over-the-Counter Remedies

Purchasing over-the-counter or natural remedies for treating intestinal parasites is never recommended. While it may seem like a faster and cheaper alternative to visiting your veterinarian, there is NO guarantee that those products are safe or effective in treating any type of medical condition, and they could actually be harmful to your dog.

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Leslie Gillette, DVM


Leslie Gillette, DVM


Dr. Leslie Gillette graduated from the University of Florida College of Veterinary Medicine in 1998. After 12 years of small animal...

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