Worms in Dogs: What You Need To Know

Diamond's Friends Pet Rescue
Jun 6
6 min read

Worms are one of the most common issues we see in dogs we pull from shelters. The good news? They are treatable! So, don’t worry too much if your dog gets diagnosed with worms.

Here’s everything you need to know about these pesky parasites.

What Are the Most Common Types of Worms Dogs Get?

According to the American Veterinary Medical Association (AVMA), dogs can be infected by many types of intestinal worms. The most common culprits include:

Hookworms
Roundworms
Tapeworms
Whipworms

Each type of worm has its own method of transmission and symptoms, which we’ll break down shortly.

What Is the Prognosis for Worms in Dogs?

The prognosis is good! Most dogs will make a full recovery from any worm infestation they may be experiencing.

How Common Are Worms in Dogs?

Worms are very common! Companion Animal Parasite Counsel reports that up to 30% of dogs under six months of age shed roundworms, and up to 60% of dogs may have tapeworms at some point in their lives.

The Counsel also reports that up to 19% of dogs in the U.S. may have hookworms, and 14.3% of shelter dogs may have whipworms.

Learn More: Common Health Issues Your Shelter Dog May Come Home With

How Are Worms in Dogs Diagnosed?

Sometimes, you can actually see worms in your dog’s poop. This is particularly true with tapeworms that look like little specks of rice in your dog’s stool.

Most of the time, worms are diagnosed through a fecal exam, where your vet will analyze a stool sample for parasite eggs under a microscope.

The AVMA recommends doing fecal tests twice annually for adult dogs.

Learn More: How To Choose a Veterinarian

How (And Where) Do Dogs Get Worms?

How dogs get worms can vary based on the type of worm. Here’s a breakdown from the AVMA:

Worm Type	How It’s Transmitted	Where Dogs Get It
Hookworms	Feces of infected animals	Direct contact with hookworm larvae that allows the larvae to penetrate your dog’s skin Eating contaminated substances or an infected animal/insect Puppies drinking the milk of their infected mom
Roundworms	Feces of infected animals	Licking contaminated paws or fur Puppies drinking the milk of their infected mom Swallowing the eggs in soil or water that’s been contaminated
Tapeworms	Infected fleas, lice, or rodents	Eating infected rodents Swallowing infected fleas or lice, typically during grooming
Whipworms	Feces of infected animals	Licking contaminated paws or fur Swallowing the eggs of soil that’s been contaminated

What Are the Symptoms of Worms in Dogs?

Symptoms can vary depending on the type of worm and the severity of the infection, but some common signs include:

Appetite changes
Bloated belly
Bloody stool
Diarrhea or vomiting
Lethargy
Scooting their butt on the ground
Visible worms or segments in stool
Weight loss

In severe cases, worms can even cause anemia or intestinal blockages.

Learn More: At-Home Health Dog Health Checks

What Health Issues Can Worms Cause in Dogs?

Worms can be dangerous to your dog. According to information from VCA and Cornell University, here’s what they can lead to if untreated:

Type of Worm	Potential Health Issues
Hookworms	Anemia Intestinal inflammation
Roundworms	Blockages The biggest danger is to puppies, who may experience stunted growth
Tapeworms	The biggest danger is to puppies, who may experience anemia, intestinal blockages, and stunted growth
Whipworms	Bloody stool General dehabilitation Weight loss

In puppies or dogs with weakened immune systems, VCA reports that heavy worm infestations can be serious. Fortunately, in most adult dogs, worms are not typically life-threatening.

Learn More: What You Should Know About Giardia in Dogs

How Are Worms in Dogs Treated?

Luckily, worms are easily treatable with the right medication. A trip to your veterinarian is needed for treatment as no at-home options exist to properly evict your pup's unwanted guests from their body.

Here's what Cornell University suggests based on the type of worms your dog has:

Type of Worm	Treatment
Hookworms	Anthelmintics are prescribed. Treatment is repeated every two to three weeks until the infection clears.
Roundworms	Pyrantel or fenbendazole are given. Repeating treatment after two weeks is advisable to ensure the infection clears.
Tapeworms	Praziquantel is given either orally, via injection, or as a tablet. Flea control is necessary for all pets in the house, and a monthly dewormer can help prevent reinfection.
Whipworms	Anthelmintics are used for treatment and must be repeated monthly for three months to eliminate the infection.

How Long Do Worms in Dogs Last?

Once treatment begins, it starts working in a few hours. You may start seeing worms in your dog’s stool after a few days. However, because of the lifecycle of worms, depending on the type of infection and severity, the length of infection can vary.

Roundworms likely need another round of medication after two weeks to clear the infection, while whipworms may take up to three months to clear.

Follow-up testing is crucial to make sure all worms are gone.

Are Worms Deadly to Dogs?

Most adult dogs are not at risk of death from worm infestation. However, severe infestations, especially in puppies or immunocompromised dogs, can be deadly.

Are Worms Contagious To Other Dogs?

Depending on the type of worm, yes. Many worms spread through contaminated environments or feces, so one infected dog can easily pass parasites to others, especially in multi-dog households or at dog parks.

Here’s a breakdown of which types of the most common worms are (and aren’t) contagious between dogs.

Type of Worm	Contagious To Other Dogs
Hookworms	Yes
Roundworms	Yes
Tapeworms	No
Whipworms	Yes

Regular deworming and hygiene are vital to preventing the spread of worms between dogs.

Learn More: Dog Parks 101

Are Worms Contagious From Dogs To People?

Unfortunately, yes. Here's a breakdown of which worms are contagious from dogs to people:

Type of Worm	Contagious To People
Hookworms	Yes
Roundworms	Yes
Tapeworms	No
Whipworms	Rarely

Again, good hygiene and regular deworming are the best preventative measures you can take.

How Long Are Dogs With Worms Contagious?

Dogs can remain contagious for as long as they’re shedding parasite eggs, which may still occur even after symptoms clear.

Remember that, depending on the type of worms, additional treatments may be needed anywhere from two weeks to three months after initial treatment. This is why follow-up testing is important.

Is There a Vaccine for Worms in Dogs?

There’s no vaccine for intestinal worms in dogs. However, some monthly flea/tick preventatives also protect against hookworms, roundworms, and whipworms, making them a great all-in-one solution for parasite prevention.

A few options include:

NexGuard Plus (doesn’t include whipworm protection)
Revolution (doesn’t include whipworm protection)
Simparica Trio (doesn’t include whipworm protection)
Trifexis

Be sure to talk to your vet about the best option for your dog, and monitor your pup when they are on these medications to ensure they don’t have an adverse reaction.

Learn More: Adult Dog Vaccine Schedule

How Can I Protect My Dog From Getting Worms?

Prevention is critical when it comes to keeping your dogs from getting worms. Here’s what you can do:

Avoid letting your dog eat feces or dead animals
Control fleas to prevent tapeworms
Don’t let your dog drink from puddles or groundwater
Pick up poop promptly
Get rid of any standing water in your yard
Take your dog to the vet for regular check-ups and fecal exams
Use year-round parasite prevention

Importantly, the American Animal Hospital Association recommends that puppies be dewormed every two weeks starting at two weeks old, then monthly until they’re six months.

Final Thoughts

Worms may be gross, but they don’t have to be scary. With a little knowledge and a good prevention plan, you can help your dog recover and and keep them worm-free!

Disclaimer: This article is not intended as professional medical advice. It is based on personal experience and online research. Please consult with your veterinarian if you are concerned about your dog's health.