A roundworm infection can be easy to miss at first because the parasite lives inside the intestinal tract and may not cause noticeable changes right away. Roundworms in dogs are picked up in several ways, including contact with contaminated environments and infected animals, and they can continue spreading if the infection is not treated.
What Are Roundworms in Dogs?
Roundworms in dogs are intestinal parasites that live primarily in the small intestine. The most common species found in dogs is Toxocara canis, although Toxascaris leonina can also infect them.
Adult worms produce microscopic eggs that leave the body in a dog’s stool. Once those eggs mature in the environment, another dog can swallow them and become infected. Puppies have an additional risk because Toxocara canis larvae can pass from their mother before birth and, to a lesser extent, through nursing.
Roundworm larvae do not always remain in the digestive tract. In young dogs, they may migrate through the liver and lungs before eventually returning to the intestine, which is why coughing can sometimes appear alongside digestive symptoms.
What Do Roundworms Look Like?
Adult roundworms look like long, smooth, cream-colored worms commonly compared to spaghetti. They may be several inches long and can occasionally appear in vomit or stool.
Finding roundworms in a dog’s poop is a good reason to call your veterinarian, but not seeing worms does not rule out an infection. In many cases, only microscopic eggs are being passed.
Signs & Symptoms of Roundworm in Dogs
Some dogs carry roundworms without looking sick, especially when the infection is mild. Puppies and dogs with a large number of worms are more likely to develop noticeable symptoms. Common signs and symptoms of roundworms in dogs include:
- Diarrhea or soft stool
- Vomiting
- Visible worms in stool or vomit
- A round or potbellied abdomen
- Weight loss
- Poor growth in puppies
- Thin body condition
- Dull or rough coat
- Reduced appetite
- Straining to poop
- Coughing
- Low energy
A heavily infected puppy can become seriously ill, and in rare cases a mass of worms may contribute to an intestinal blockage.
Call your veterinarian promptly if your puppy is vomiting repeatedly, losing weight, not eating, or seems unusually weak. A painful or swollen abdomen, collapse, severe breathing trouble, or repeated vomiting calls for emergency care.
What Causes Roundworm in Dogs?
When pet parents ask about the causes of roundworms in dogs, there are several possible answers. Puppies are especially vulnerable, but adult dogs can pick them up from the environment too.
Common causes of roundworm infection include:
- Before birth: Dormant Toxocara canis larvae in a pregnant dog can become active and pass to her puppies before they are born.
- Nursing: Puppies can also be exposed to larvae through their mother’s milk.
- Contaminated soil or feces: Dogs may swallow infective eggs while sniffing, licking their paws, eating soil, or exploring areas contaminated with feces.
- Eating prey: Rodents, birds, and other small animals can carry roundworm larvae in their tissues.
- Shared outdoor spaces: Yards, parks, kennels, and other areas used by many dogs can become contaminated when infected stool is not removed.
Roundworm eggs are hardy. After becoming infective, they can survive in suitable soil for months or even years, which makes regular stool cleanup particularly important.
How Veterinarians Diagnose Roundworm Infection
A veterinarian will usually start with your dog’s history, symptoms, and a physical exam. They may ask about age, recent deworming, parasite prevention, outdoor activity, and whether you have seen anything unusual in the stool or vomit.
A fecal flotation test is commonly used to look for microscopic roundworm eggs. Antigen testing or PCR may also help identify infections when only a small number of worms are present or when young worms have not begun producing eggs yet.
Because dogs can carry more than one intestinal parasite at the same time, testing also helps make sure treatment covers what is actually present.
Bring a fresh stool sample if your veterinary clinic requests one. If you have seen a worm at home, a photo can provide another useful clue.
Treatment: How to Treat Roundworms in Dogs
The first step of effective treatment for roundworm in dogs is confirming the parasite and choosing an appropriate dewormer. Several veterinary medications can kill roundworms, but the ideal product and dosing schedule should be based on your dog’s age, weight, health, and parasite history.
Canine roundworm treatment often includes:
- A veterinarian-recommended deworming medication
- Repeat doses to target worms as they mature
- Follow-up fecal testing
- Ongoing monthly parasite prevention
- Fluids or other supportive care if vomiting or diarrhea has caused dehydration
Very young puppies usually need a scheduled series of deworming treatments rather than a single dose. CAPC recommends beginning puppy deworming at two weeks of age and repeating it every two weeks until regular broad-spectrum parasite control begins.
If you’re researching how to get rid of roundworms in dogs, one of the most important notes is not to stop treatment simply because visible worms disappear. Your veterinarian may want to repeat testing to make sure the infection has actually cleared.
Prevention: How to Prevent Roundworm in Dogs
Preventing roundworms in dogs is largely about reducing exposure and keeping parasite control consistent.
Helpful steps include:
- Use year-round parasite prevention. Ask your veterinarian for a product that protects against roundworms and fits your dog’s lifestyle.
- Follow the puppy deworming schedule. Puppies need more frequent treatment and testing during their first year.
- Pick up stool promptly. Remove waste from your yard daily and clean up immediately during walks.
- Prevent scavenging and hunting. Eating rodents or other prey can expose dogs to roundworm larvae.
- Keep play areas clean. Protect sandboxes, gardens, and children’s play areas from animal feces.
- Wash your hands after handling waste. Good hygiene reduces the chance of accidentally ingesting roundworm eggs.
- Keep up with fecal testing. CAPC recommends more frequent testing for puppies and at least twice-yearly testing for adult dogs based on health and lifestyle.
Even dogs on preventive medication still benefit from routine stool checks because no prevention plan removes every possible exposure.
Need Veterinary Assistance? Find an UrgentVet Near You!
Roundworms are common, treatable, and usually do not require an emergency hospital visit. If you have spotted worms in your dog’s stool or vomit, or your dog is showing possible parasite symptoms, UrgentVet can provide same-day diagnosis and treatment.
Are you searching for immediate urgent care for your pet? Find an UrgentVet near you to walk in or check in online.
Roundworms in Dogs FAQs
How Do I Treat Roundworms in Dogs at Home?
For pet parents searching for information about how to treat roundworms in dogs at home, online instructions can sometimes be misleading – or even dangerous. Avoid homemade remedies or leftover dewormers. Different parasites require different medications, and dosing needs to be appropriate for your dog. All medication should come from (or be recommended by) a veterinarian.
How Fast Do Roundworms Grow in Dogs?
After a dog becomes infected, larvae develop and eventually mature into egg-producing adults. In puppies, Toxocara canis can begin producing eggs within a few weeks. The exact timeline for how fast roundworms grow in dogs depends on how the infection was acquired and the dog’s age.
How Long Does It Take for a Dog to Get Rid of Roundworms?
Adult worms may die soon after effective deworming, and you may notice them in the stool afterward. Completely clearing an infection and getting rid of roundworms can take several weeks because repeat treatment may be needed as immature worms develop. Follow the full schedule your veterinarian provides.
Are Roundworms in Dogs Contagious to Humans?
Yes, roundworms in dogs are contagious to humans. Toxocara canis can infect people, but transmission usually happens when someone accidentally swallows infective eggs from contaminated soil, feces, or unwashed hands rather than through ordinary contact with a dog. In uncommon cases, larvae can affect internal organs or the eyes.
Can I Touch My Dog if They Have Roundworms?
Yes, you can touch your dog if they have a roundworm infection. You do not need to avoid petting or handling your dog. Wash your hands after cleaning up stool, before eating, and after working in soil or areas where animals eliminate. Keep children away from contaminated feces and encourage regular handwashing.
Can Roundworms Cause Bloody Diarrhea in Dogs?
Roundworms more commonly cause diarrhea, vomiting, poor growth, or a potbellied appearance. Blood in the stool can occur with gastrointestinal irritation, but it may also point to another parasite or medical problem. Contact your veterinarian if you notice bloody or black stool.
Do I Need to Clean My House if My Dog Has Roundworms?
If your dog has roundworms, focus on removing feces quickly. If your dog has an accident indoors, clean the area thoroughly and wash contaminated bedding. Routine whole-house disinfection is generally less useful than preventing stool from remaining in the environment, because roundworm eggs are extremely resistant once present.
What Are the Symptoms of a Dog Having Roundworms?
A dog may have no symptoms at all. When signs do occur, common ones include diarrhea, vomiting, weight loss, a potbellied abdomen, poor growth, coughing, and a dull coat. Puppies tend to show more obvious illness than healthy adult dogs.
What Kills Roundworms in Dogs?
Veterinary deworming medications containing drugs effective against roundworms in dogs can kill the parasites. Several options are available, so your veterinarian can choose one based on your dog’s age, weight, health, and prevention plan.
Is a Roundworm Infection an Emergency for Puppies and Dogs?
Most cases of roundworm infection in dogs can be handled through a regular or same-day veterinary visit. For puppies, a roundworm infection is critical needing quick attention at an urgent pet clinic or emergency vet . Puppies should be seen promptly because heavy infections can affect them more severely. Go to an emergency hospital for collapse, severe weakness, significant breathing trouble, repeated vomiting, or a swollen, painful abdomen.
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