Roundworms are common intestinal parasites in dogs and cats, especially puppies and kittens. They can cause digestive problems, interfere with growth, and sometimes be visible in a pet’s stool or vomit. In other cases, there may be no obvious signs at all.
Because roundworms are treatable, an infection is usually manageable once it has been identified. The more important issue is knowing when to test, treating the right parasite, and reducing the chances of your pet becoming infected again. Certain roundworms can also infect people, which makes good parasite control important beyond your pet’s health.
What Are Roundworms?
Roundworms are parasites that live in the intestinal tract of infected dogs and cats. Adult worms are long, pale, and thin, and are often compared to strands of spaghetti.
Infected animals pass microscopic roundworm eggs in their feces. Those eggs can contaminate soil, yards, litter areas, and other places where animals spend time. Dogs and cats are affected by different species of roundworms, but both can become infected through their environment and, in some cases, through other animals.
How Do Dogs and Cats Get Roundworms?
One of the most common ways pets become infected is by swallowing roundworm eggs from a contaminated environment. A dog might encounter them while sniffing or digging in soil, for example, then ingest them directly or later while licking its paws. Cats can be exposed in similar ways.
Rodents and other small animals can also carry immature roundworms, so pets that hunt and eat prey have another potential route of exposure.
Puppies have a particularly high risk because some roundworms can pass from the mother to her puppies. Kittens can acquire certain roundworm infections through nursing. This is why deworming and parasite screening begin early in a puppy or kitten’s veterinary care, rather than waiting until there is a visible problem.
Can Indoor Pets Get Roundworms?
Indoor pets have fewer opportunities for exposure, but they are not completely protected from roundworms. Contaminated soil can be tracked indoors, an indoor cat may catch a mouse, or a pet may already be infected when it enters the household.
An indoor lifestyle is one factor we consider when assessing parasite risk, but it does not replace routine screening.
Signs of Roundworms in Dogs and Cats
The signs of a roundworm infection can vary quite a bit. Young animals and pets with heavier infections are more likely to show noticeable symptoms.
These may include:
- A pot-bellied appearance, particularly in puppies and kittens
- Diarrhea
- Vomiting
- Poor growth or difficulty gaining weight
- Weight loss
- A dull coat
- Coughing in some cases
- Worms visible in stool or vomit
A heavily infected puppy or kitten may have a rounded abdomen while otherwise looking thin or failing to grow normally.
Adult pets may show much less. Some dogs and cats with roundworms have normal appetites, normal stools, and no outward signs of infection. This is one reason fecal testing is useful even when a pet appears healthy.
What Do Roundworms Look Like?
Adult roundworms are usually white or cream-colored, long, and thin. When they are passed in stool or vomited up, they may resemble cooked spaghetti.
Many pet owners never see an adult worm, even when their pet is infected. The eggs used to diagnose most infections are microscopic and cannot be seen in the stool without testing.
If you do find something that looks like a worm, bring a fresh stool sample to your pet’s appointment if possible. A clear photo can also be helpful if you are unable to collect what you saw.
How Are Roundworms Diagnosed and Treated?
Veterinarians commonly diagnose roundworms through a fecal examination. A stool sample is tested for evidence of parasite eggs, allowing us to find infections that may not be obvious from a pet’s appearance or symptoms.
Once roundworms are identified, treatment usually involves an appropriate deworming medication. More than one treatment may be needed because of the parasite’s life cycle, and your veterinarian may recommend follow-up testing afterward.
Puppies and kittens are often dewormed on a schedule during their early veterinary visits because roundworm infections are so common at that age.
It can be tempting to pick up an over-the-counter product labeled “dewormer” when you see something suspicious in your pet’s stool, but knowing which parasite is present makes a difference. Roundworms are only one of several intestinal parasites that affect dogs and cats. Hookworms, whipworms, tapeworms, Giardia, and other parasites can cause some of the same symptoms, and treatment is not interchangeable.
Testing gives us a much better answer than guessing at the cause.
Can Humans Get Roundworms From Dogs or Cats?
Certain roundworms found in dogs and cats are zoonotic, meaning they can infect people.
Human exposure is generally associated with accidentally ingesting microscopic eggs from an environment contaminated by infected animal feces. Simply touching or petting a dog or cat with roundworms is not the usual route of infection.
Children can have more opportunity for exposure because they play in soil or sand and are more likely to put their hands near their mouths. Promptly picking up dog waste, keeping litter boxes clean, washing hands after handling pet waste, and keeping children’s play areas free of animal feces all help reduce that risk.
A roundworm diagnosis in a pet is not a reason to panic. It is a reason to treat the infection and pay attention to sanitation while doing so.
Preventing Roundworms in Dogs and Cats
Because you cannot rely on seeing worms or waiting for symptoms, prevention works best as a combination of routine veterinary care and some fairly simple habits at home.
That includes:
- Using veterinarian-recommended parasite prevention as directed
- Keeping up with routine fecal examinations
- Following the recommended deworming schedule for puppies and kittens
- Picking up dog waste promptly
- Cleaning litter boxes regularly
- Limiting hunting and rodent exposure when possible
- Washing hands after handling pet waste or working in potentially contaminated soil
- Keeping children’s play areas free of animal feces
For pets in Tallahassee, parasite control is not something we generally view as a short seasonal concern. Florida’s warm climate allows many parasites to remain active for much of the year, so consistent prevention tends to make more sense than stopping and restarting protection based on the season.
The right prevention plan will also depend on the individual pet. Age, lifestyle, travel, hunting habits, exposure to other animals, and other factors can all change the level of risk.
When Should Your Pet See a Veterinarian?
If you see worms in your pet’s stool or vomit, have your pet checked. Persistent diarrhea or vomiting, unexplained weight loss, a pot-bellied appearance in a puppy or kitten, or poor growth in a young animal are also reasons to schedule an appointment.
It is also a good idea to test a newly adopted puppy, kitten, stray, or rescue animal when the parasite-prevention history is unknown. The same applies to pets that are overdue for routine fecal screening.
You do not need to wait until worms are visible to find an infection.
