What the Fluff?

Why Are There Worms in My Dog’s Poop?

Intestinal parasites like tapeworms and roundworms are common in dogs, but can be treated safely and effectively with help from your veterinarian. Find out how to diagnose, treat, and prevent worms in your dog.
By Lacey Howard August 24, 2020 Advertisement Pin FB More Tweet Email Send Text Message Print

Like it or not, it's a good idea to take an occasional peek at your pup's poop. No, really. Poop can say a lot about your dog's health. If you spy worms in your dog's excrement, you're looking at tapeworms (flat white worm segments ¼ to ½ inch long that may be wriggling) or roundworms (off-white or tan lengths resembling spaghetti). If you see either of these worms in your dog's poop or clinging to the fur around your pet's anus, call your veterinarian.

woman picking up dog poop; why are there worms in my dog's poop? Credit: cherryandbees / Adobe Stock

How Do Dogs Get Worms?

Many puppies (and kittens) are born with roundworms that are passed from the mother's uterus or milk. Having little ones wormed is important because roundworms can stunt growth and even cause death by blocking intestines. In addition, the feces of infected animals, in turn, infect the soil (for years!) and other animals who come in contact with that soil or feces.

Dogs (and cats) get tapeworms by eating fleas or other animals that are infected or have fleas that are carrying tapeworm eggs. "Microscopic eggs can easily be ingested without the pet owner knowing, and the worms then develop inside the dog," Anne Conover, DVM, the owner of Rolling Hills Veterinary Clinic, a mixed animal practice in Madison County, Iowa, says. Flea control is an effective way to avoid tapeworms.

How Can You Tell if Your Dog Has Worms?

Seeing worms in your dog's feces is a sure way to diagnose roundworms and tapeworms. If you see worms in your dog's stools, contact your veterinarian. However, there are several other types of intestinal parasites that can infect and affect your dog that are not seen with the naked eye.

"Most of the time you won't see the worms themselves, as the worm eggs are usually the only evidence shed in the stool, and the eggs are microscopic," Conover says. "Some types of worms will exit with the stools, such as tapeworms (which look like grains of rice) and if there is a very large worm burden, other types of adult worms will exit with the stools."

Hookworms and whipworms burrow into the intestinal lining, and it's less likely that you'll see these worms visible in your dog's poop. Their eggs, however, will be excreted by infected dogs.

If you see maggots (fly larvae), earthworms, or red worms (red wrigglers) in your dog's poop, it's likely because those creatures are highly attracted to and feed on the feces. So they likely showed up quickly after your dog's bowel movement (rather than being included when it exited his body).

While worms might be hard to spot in your dog's poop, there are some clues to look for: While many infected dogs have normal bowel movements, you may notice physical symptoms such as diarrhea, vomiting, blood or mucous in the stool, weight loss, poor coat, and abdominal discomfort or enlargement. The surest way to know if your pup has worms is to have his stool tested by a veterinarian.

How Are Worms Treated?

Treatment for intestinal parasites is best done by a veterinary professional. "Call your veterinary care team. They will advise you on diagnosis and types of dewormer to treat the problem. They may recommend you bring a stool sample in for testing to confirm the types of worms before treating," Conover says.

In addition, she says, an annual fecal exam should be performed by your veterinarian to make sure your dog is free of worm eggs before they mature into adults. "Puppies, particularly newborns, have a frequent deworming schedule—as recommended by a veterinarian—until they are old enough to start on preventatives," Conover says.

If your dog is diagnosed with worms, the deworming process includes administering a medicine that is poisonous to the worms but safe for your pet. The medication is given orally (as a chewable tablet or a liquid) or by injection and requires at least two doses (sometimes as many as six or more), spaced two weeks apart. The first kills the current worms and the second kills those that, in the meantime, hatched from eggs in the intestine. After deworming medication is given, you may see worms in your dog's poop, or even in his vomit. This is a normal reaction that is simply removing the (now dead) worms from your dog's body.

Prevent Worms in Dogs

The first step to preventing worms is basic sanitation and hygiene. Pick up after your dog—both in public places and in your own yard—to prevent other dogs from eating his poop (gross, but it's a normal dog thing) and to avoid contaminating the soil. Contaminated soil can lead to your dog getting worms because worm eggs or larvae stick to your dog's feet, and when the dog grooms himself, they enter his mouth and result in an infestation. Finally, Conover says, "Minimize direct contact with stray dogs and other animals, and do not let your dog sniff or eat other animals' feces."

To prevent passing your dog's worms to humans, always use a plastic bag when you pick up after him, and wash your hands as soon as possible. Don't let your dog use a playground or sandbox (or any place where children regularly play) as a litter box—children can contract worms by putting dirty fingers in their mouths.

"The best way to prevent and treat worms consistently is to use a monthly product that is both a heartworm preventative and an intestinal parasite preventative," Conover says. "You should also be using a flea and tick preventative to prevent worms and other diseases spread by these pests. Ask your veterinarian which products are best for your dog and your geographical location."

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