roundworms and nematodes in pets

Roundworms are one of the most common intestinal parasites in dogs and cats. Here’s what to know and how to help reduce the risk for your pet.

Weight loss, stunted growth, or worms in your pet’s poop or vomit? Your pet needs safe and effective deworming to help rid their body of contagious parasites.

Roundworm is spread to both people and pets via contaminated soil.

Parks, playgrounds, play areas, and more can be contaminated with roundworm eggs. Different varieties can affect different species, including humans, so practice good hygiene and help your pet with good preventive care.

What to know about roundworms

The term “roundworm” refers to a few varieties of extremely common intestinal parasites in pets, including Toxoscara leonina, Toxocara cati, and Toxicara canis. Some of these varieties are found in dogs, while others affect cats, and even people. 

Despite their name, adult roundworms aren’t round but long, tubular squiggles. Each worm can grow to be up to six inches long, which is why a big worm infestation can bloat your pet’s stomach even if they’re losing weight. 

Roundworms have a complex life cycle. Once eggs are ingested by their new host, they hatch into larvae inside the intestinal tract. These larvae then migrate through different body tissues, including muscles, liver, and lungs and become dormant cysts. 

Dormant roundworm cysts don’t activate all at once but can linger for months and even years. Once activated, the larvae return to the intestine to become full-grown parasites that drain nutrients and lay eggs into exiting stool. 

Roundworms are especially dangerous to vulnerable puppies and kittens. An infestation can steal many important nutrients from young dogs and cats.

Do pets get roundworm from dog feces and dirty cat litter?

Roundworms are an extremely common parasite and can happen to even the most well-loved, best cared for pet. This parasite can spread in a few different ways.

Contaminated environments:

Pets of all ages can pick up roundworm eggs by sniffing, licking, or contacting infected feces, which can contaminate soil or sand and even plants with infectious roundworm eggs.

Eating roundworm eggs in wild animals:

Many small animals such as rats, earthworms, cockroaches, and birds don’t actually get roundworms, but act as carriers (paratenic hosts) for the parasite.

Prenatally or through mother’s milk:

Roundworm cysts can activate after estrus in unspayed female dogs, turning into larvae that cross the placental barrier to infect puppies in the womb. Larvae can also infest mammary glands and spread to puppies and kittens while nursing.

Dormant larvae:

Pets exposed to roundworms carry dormant cysts that resist deworming, which means that pets can develop new active infections months or even years after being treated for worms.

Signs of a roundworm infection in dogs and cats

Veterinarians typically diagnose roundworm by performing a fecal flotation test to find roundworm eggs in your pet’s poop. However, due to the roundworm life cycle, finding those eggs isn’t always easy.

If your pet is showing any combination of the symptoms below, it’s time for a vet visit — especially for vulnerable puppies and kittens, whose symptoms may be more pronounced.

How easy is it to get roundworm from a puppy or kitten?

Some kinds of roundworm are zoonotic, which means that they’re contagious to both pets and people. The most common is Toxocara canis, which affects both people and dogs. 

In order for people to catch these kinds of worms, they have to actually ingest roundworm eggs, which are commonly found in playgrounds and parks and can survive there for many years. Small children who eat dirt or put their hands in their mouths are especially at risk. 

You can help prevent the spread by making sure your pet is dewormed on a vet-recommended schedule. Plus, your veterinary team may be able to recommend certain kinds of parasite control that can help prevent worms.

If you suspect you or any member of your human family have roundworms, please see your human doctor. 

Why it’s important to deworm your pet

Roundworms are extremely contagious. Pets can shed roundworm eggs in their poop without showing any visible symptoms. Plus, because infection can happen in the womb, infected puppies can pass contagious poop as early as 11 days after birth.

Not protecting or treating your pet can spread roundworms to pets and humans in your household, especially to small children. As for your pet, if left untreated they will continue to suffer an ongoing drain on their health — and unknowingly spread contagious eggs in their stool.

Tips on getting rid of worms in dogs and cats

Although home remedies like turmeric and coconut may be popular online, there’s no proof that they’re effective in preventing or treating roundworms. At best, these “cures” may not hurt your pet, but they’ll still have worms. 

An active roundworm infestation is treated with safe and effective deworming medications provided by your veterinarian. Since not all larvae will be active at one time, your pet may need several rounds of medication to help fight the parasite.

How can I help prevent toxocariasis (roundworms) in my pet? 

You can help your pet avoid roundworms by bringing them in for regular fecal exams and deworming and with regular parasite prevention. 

Always complete all deworming medications as prescribed. Remember, even if your pet’s poop looks normal, they can still have worms!