My dog has worms in his poop. What do I do?

Types of Intestinal Worms Found in Dogs

The presence of worms in your dog’s stool is a serious problem, one that needs to be addressed immediately. But treatment for intestinal worms in dogs can vary depending on the type of worm, and unfortunately, several types of worms can infect your dog’s GI system, all with varying degrees of symptoms.

Roundworms

Roundworms are arguably the most common intestinal parasite reported in young puppies. They appear as large, round-bodied worms with tapering ends. They attach themselves to the mucosal lining of the small and large intestine, causing diarrhea in young dogs.

Intestinal parasites are usually transmitted through the fecal-oral route. This means a dog needs to ingest water or food contaminated with the infective stage of the parasite to become infected. Roundworms are special in the sense that they can be transmitted through processes other than fecal-oral transmission. Certain species of roundworms can be transmitted from a pregnant female dog to its fetuses via the placenta.

This alternative mode of transmission for roundworms is the reason why they’re the most reported worm infection in young puppies. Another reason is most adult dogs are resistant to roundworm infections and can tolerate mild infections without any clinical signs. Often, adult dogs infected with roundworms will only show clinical signs such as vomiting and diarrhea if the worm infection is already severe.

Hookworms

Hookworms, or ascarids, are another type of intestinal parasite commonly found in dogs. They mostly affect young puppies but older dogs can also become infected. Hookworms appear as round, long worms in a dog’s stool. Hookworms attach themselves to the mucosal lining of the dog’s intestinal tract and cause damage and inflammation to the intestines, resulting in diarrhea that is often bloody.

Like roundworms, hookworms can infect dogs through means other than fecal-oral transmission. Certain species of hookworms can migrate to the mammary glands of a nursing female dog and can be ingested by her young puppies. Some species can penetrate a puppy’s skin, migrate towards the lungs, and are usually coughed out and swallowed back, causing an infection.

Whipworms

Whipworm is another type of roundworm that is usually found in the latter segments of the intestinal tract, particularly the cecum and colon. They get their name from their physical appearance, having a narrow proximal end and a wide caudal end, giving the appearance of a bullwhip.

They attach themselves to the mucosal lining of the large intestine, causing bleeding and diarrhea in dogs. Mild infections of whipworm do not usually cause any clinical signs in dogs, but as the number of worms increases, affected individuals will start to have bloody and mucousy diarrhea that often has a pungent smell.

Tapeworms

Tapeworms, also called cestodes, can also infect dogs, but most infections do not result in serious diseases. Unlike previously described intestinal worms, tapeworms are different in the sense that they don’t have similar physical characteristics. Instead of having one, singular body, adult tapeworms have segmented bodies.

Tapeworm segments, called proglottids, each have eggs inside and break off to be passed out in the dog’s feces. These segments often appear as white specks in the dog’s stool and will look similar to a grain of rice or sesame seed. These segments are often the infective stage of tapeworms. However, unlike other intestinal parasites, dogs do not become infected when they ingest proglottids from the feces of an infected dog.

Tapeworms require an intermediate host, in this case, fleas, to infect other dogs. Proglottids excreted via the feces from an infected dog are ingested by fleas before they jump onto and attach to another dog’s skin. A dog then becomes infected when they ingest fleas that have tapeworm proglottids in them.

How do you treat intestinal worm infections in dogs?

Most intestinal worm infections in dogs respond well to treatment. Commercially available deworming medications such as Praziquantel or Pyrantel, which come in tablet or oral suspension, are often effective enough to kill adult worms. A series of deworming treatments, usually given 2 weeks apart, is often needed to completely eradicate worm infections in dogs. This is because immature worms are often not affected by deworming medications until they become fully mature, which usually takes an average of 2 weeks.

Tapeworms, unlike other intestinal worms, are difficult to completely eradicate. Because of their segmented bodies, continuous dosing of deworming medicine is needed. Giving only one dose or if doses are spread too far apart, allows some segments to survive, and the tapeworm will be able to grow and replicate again.

Preventing Intestinal Worm Infections in Dogs

Good sanitation is key in preventing worm infection in dogs, especially in multiple dog households. Keeping food and water bowls clean and free from contamination contributes greatly to controlling the transmission of intestinal worms between dogs.

Regular deworming doses, usually given every 3 to 6 months, also help control intestinal worm infestation in dogs. Puppies need to receive a series of deworming doses as early as 2 weeks of age to prevent transmission of intestinal worms among the litter.

Pregnant dogs need to be dewormed before and/or during pregnancy to prevent transplacental transmission of roundworms to the fetuses.

External parasite control in the form of topical and oral tick and flea preventives is essential in controlling tapeworm infection.

Be sure to talk to your vet about the type of deworming treatment that is best for your dog. Proper identification of the parasite and an appropriate treatment and prevention plan are key to maintaining your dog’s health.

Read more:

Coccidia in Dogs and Cats

Giardia in Dogs and Cats

Deworming Your Dog - Q&A

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