Worms in Dogs: Types, Symptoms, Treatment and Prevention

Types of Worms in Dogs

• Roundworms (Toxocara canis and Toxascaris leonina): long, pale worms several inches long. Many puppies are born with them or catch them from their mother.^13,7 See roundworms in dogs.
• Hookworms (Ancylostoma and Uncinaria): small worms that attach to the gut wall and feed on blood. They can cause severe anemia in puppies.^14,8 See hookworms in dogs.
• Whipworms (Trichuris vulpis): can cause diarrhea, which may be bloody in heavy infections, along with weight loss. Their eggs survive in soil for years.⁹
• Tapeworms (Dipylidium, Taenia and Echinococcus): flat, segmented worms that dogs catch from fleas or by eating prey. Flea tapeworm segments look like grains of rice.^15,16 See tapeworms in dogs.

Heartworm is a different parasite: it lives in the heart and blood vessels rather than the gut and is spread by mosquitoes. Giardia, another common cause of diarrhea, is a single-celled parasite rather than a worm; it was found in about 13% of dogs in the dog-park study.³

Signs of Worms in Dogs

• Diarrhea, sometimes with blood^9,6
• Vomiting, sometimes with worms in the vomit^7,10
• A pot-bellied look, poor growth or a dull coat in puppies^7,10
• Weight loss^9,6
• Pale gums and weakness from blood loss (hookworms)⁶
• Rice-like segments around the anus or on the stool, and scooting (tapeworms)^17,16
• Coughing in young puppies (roundworm larvae in the lungs)¹⁰

Many infected dogs, especially healthy adults, have no signs, which is why routine testing matters.^7,8,1

How Do Dogs Get Worms?

• From their mother: roundworms before birth or through her milk, and hookworms through her milk.^7,14
• From the environment: swallowing eggs or larvae in soil, grass or feces, or hookworm larvae burrowing through the skin.^13,14
• From fleas: swallowing an infected flea while grooming (the most common tapeworm).¹⁵
• From prey and raw meat: eating rabbits, rodents or uncooked offal (other tapeworms).^18,19

Worm eggs are tough. Roundworm and whipworm eggs can stay infective in soil for years, so a contaminated yard can keep reinfecting dogs.^13,9

Testing and Treatment

Vets diagnose most worms with a fecal (stool) test. Tests can miss some infections: tapeworms are often missed, and newer antigen tests find more worm infections than the standard microscope test alone.^15,3 The Companion Animal Parasite Council recommends stool testing at least four times in a puppy's first year and at least twice a year for adults.¹

Treatment is a dewormer chosen by your vet for the type of worm. Different drugs target different worms, and many need repeat doses because they kill adult worms but not all larvae.^7,6 No single dewormer covers every worm (tapeworms, for example, need specific drugs), and some hookworms are now resistant to several drugs, so a vet-guided plan and a follow-up stool test are important.^15,14,20

How to Prevent Worms in Dogs

• Deworm puppies early and often, starting at about 2 weeks old and repeating every 2 weeks, with nursing mothers treated at the same time, as your vet advises.^13,1
• Use a year-round broad-spectrum parasite preventive that covers intestinal worms, heartworm and fleas.¹
• Control fleas to prevent the most common tapeworm.^16,17
• Pick up feces promptly, clean the yard regularly and cover children's sandboxes.¹
• Prevent hunting and scavenging, and don't feed raw offal.^18,21,1
• Keep up with stool tests even when your dog seems healthy.¹

Can People Get Worms From Dogs?

Yes. Roundworm eggs swallowed from contaminated soil can cause toxocariasis, which can damage the eyes; in one year, surveyed US eye doctors reported 68 new cases, with a median age of 8.5.^22,4 Hookworm larvae can burrow into bare skin and cause itchy, winding tracks (cutaneous larva migrans).⁵ Children are most at risk, so wash hands after handling dogs or soil, and avoid walking barefoot where dogs defecate.^4,5

See diarrhea in dogs.

Frequently Asked Questions

What are the signs of worms in dogs?

Diarrhea, vomiting, a pot belly in puppies, weight loss, pale gums, scooting or rice-like segments. Many dogs show no signs.

What do worms in dog poop look like?

Roundworms are long, pale, round worms several inches long; tapeworm segments look like grains of rice. Hookworms and whipworms are small and rarely seen, so they're usually found with a stool test.

How do dogs get worms?

From their mother, from contaminated soil or feces, by swallowing fleas, or by eating prey or raw meat.

Can I treat my dog for worms at home?

No single dewormer covers every type of worm, and some hookworms resist common drugs. A stool test and a vet-recommended dewormer are more reliable.

How often should I deworm my dog?

Puppies need frequent deworming from about 2 weeks old. Adults are best protected by a year-round preventive plus regular stool tests.

Can humans get worms from dogs?

Yes. Roundworms and hookworms can infect people, especially children. Good hygiene and picking up feces lower the risk.

Are worms in dogs an emergency?

Usually not in adults, but heavy hookworm infections can be life-threatening in puppies. Pale gums or weakness need prompt care.