Ask the Vet - Understanding Intestinal Parasites in Pets

Dr. Lopez, DVM:

"How do I know if my pet has worms?"

Intestinal parasites are more common than you think. Learn how to spot the signs and keep your pet safe.

Intestinal parasites are small organisms that live in your pet’s digestive system. Some are so tiny they can only be seen under a microscope, while others are visible to the naked eye. These parasites feed off your pet, and in some cases, they can even spread to people.

What Are the Three Most Common Intestinal Parasites in Pets?

1. Tapeworms

How pets get them: Pets usually get tapeworms by swallowing an infected flea — often while grooming or biting at itchy skin.

What you might see: You may notice small white, rice-sized pieces (called proglottids) in your pet’s poop or stuck around their rear. These are segments of the tapeworm that contain eggs and can infect other animals.

Symptoms: Many pets don’t show signs, but some may have mild vomiting or diarrhea.

Diagnosis: If you see the rice-like pieces, that’s often enough for your vet to diagnose. A fecal test can confirm infection.

Treatment: We recommend both deworming medication and monthly prescription flea prevention. If fleas are in your home, it may take up to 3 months of consistent flea control to eliminate them fully. A second deworming 2–4 weeks after the first can help prevent reinfection. We offer both treatments at all CAMP Vaccine Clinics.

Can humans get tapeworms? It’s rare, but possible — usually by accidentally swallowing an infected flea.

2. Roundworms

How pets get them: These spaghetti-like worms are the most common intestinal parasite in puppies and kittens. They can be passed from mother to baby before birth or through nursing. Pets can also get them from the environment or by eating infected prey.

What you might see: You may notice white, spaghetti like worms in your pet’s stool or vomit. Puppies and kittens often develop a round “pot-bellied” look.

Symptoms: Vomiting, diarrhea, and a bloated belly — especially in young animals.

Diagnosis: While you might see the worms, a fecal test from your vet is still recommended to confirm.

Treatment: Routine deworming is part of every puppy and kitten vaccine visit. Pyrantel is a common dewormer used and is available at CAMP Vaccine Clinics. Monthly parasite preventatives like Simparica Trio (dogs) or Revolution Plus (cats) also help protect against roundworms.

Can humans get roundworms? Yes. Roundworms can spread to humans, especially through contact with contaminated soil or feces. Always wash hands after handling pets or cleaning up after them.

3. Giardia

How pets get it: Giardia is a microscopic parasite found in contaminated water, food, or surfaces like bedding and toys. Pets can also reinfect themselves through grooming.

Symptoms: Some pets show no signs. Others have intermittent or ongoing diarrhea, and long-term infections can lead to weight loss.

Diagnosis: A fecal test from your vet is needed to confirm Giardia.

Treatment: Your vet will prescribe a specific dewormer. Because Giardia can survive in the environment, it’s important to bathe your pet and thoroughly clean their living areas. Sometimes multiple rounds of treatment are needed.

Can humans get Giardia? Humans can get a form of Giardia, but the strains that affect pets don’t often infect people. Still, good hygiene is important — always wash your hands after handling pet waste.

General Parasite Prevention Tips

• Deworm puppies and kittens at every vaccine appointment.

• Submit a fecal test for each pet 1–2 times a year.

• If your pet isn’t on a monthly preventative, consider routine deworming 2–4 times a year.

• Pick up pet waste promptly.

• Wash hands or wear gloves when handling poop, cleaning the litter box, or working in the garden.

*A Quick Reminder: If your pet ever has unexplained vomiting or diarrhea, a fecal test is often one of the first steps your vet will take to find out what’s going on. Be sure to bring a fresh stool sample (within 24 hours) to your appointment.

To submit a fecal sample to CAMP, your pet must have had a physical exam with us within the past year.

Learn more at:  petsandparasites.org