white puppy walking through grass

Intestinal Worms In Dogs: Causes, Symptoms and Treatment


This article is written by Pet Circle's qualified veterinarian, Dr Maree Monaghan BVSc (Hons) and updated by Dr Michelle Wong BVSc

Australians love dogs and it is estimated that there are 6.3 million pooches of all shapes and sizes sharing their love with us! The joy that they bring us is endless however, caring for a dog (or three!) comes with the responsibility of ensuring their health and wellbeing.

There is one group of parasites that can silently invade our homes and cause serious harm, not only to our dogs' health, but also our own. Worms can infect dogs and humans and not cause any obvious signs of illness, so having an effective treatment and prevention strategy against worms is crucial to protect the health of your dog and your family.

To keep these sneaky invaders at bay you need to:

How Do Dogs Get Worms?

Dogs become infected with worms in a number of ways:

  • Direct contact with infected faeces or soil
  • Drinking contaminated water
  • Consumption of infected carcasses, raw meat or prey
  • Ingestion of fleas
  • From their mother before or after birth

Types of Worms in Dogs


What Do Dog Worms Look Like?

Worm eggs may be detected in faecal samples under the microscope. Your veterinarian will suggest faecal testing if they are suspicious that your dog may have worms.


Adult roundworms are long, white and look like spaghetti. The larvae of this worm can pass through the placenta and infect pups before they are born, as well as be ingested through the mother's milk.


Hookworms get their name from the hook-like appearance of their head. They are much smaller than roundworm and have fierce looking hooked mouthparts which they use to attach to the intestinal wall to feed on blood. The larvae of these worms can also be passed on through the placenta and via mother's milk.


Whipworms are around 4 cm long and have a thin front end and a thick tail which makes them look like a whip. They live in the large intestines of dogs and, unlike other intestinal worms, are more common as dogs get older.


Tapeworms are long, flat, segmented worms that attach to the wall of the small intestine with their hook-like mouthparts. They can reach up to 30 cm long and the small segments that break off and are passed out in dogs' faeces resemble grains of rice.

Tracheal Worm (uncommon)

A type of lungworm that lives in nodules in the trachea (windpipe) of dogs has recently become a problem in some areas of northern Queensland. Puppies can become infected from the faeces or saliva of an infected dog.

Rat Lungworm (uncommon)

Infection with this worm is fortunately uncommon, however, the problems it causes are very serious. Dogs can be infected with the larvae of this parasite by ingesting slugs, snails or rats. These larvae travel from the intestine through the bloodstream and end up in the brain and spinal cord causing severe inflammation of the nervous system.

Symptoms of Worms in Dogs


Signs of worm infestations in dogs can include:

Itchy Bottom

This is commonly thought of as being the most obvious sign of an intestinal worm infection in dogs, however, this is rarely true. The major cause of dogs rubbing their bottom on the ground or "scooting" is actually anal gland problems.

Bloated Stomach

A "pot belly" is a very obvious sign of intestinal worm infections in puppies.

Diarrhoea and Vomiting

Hookworm infections can cause diarrhoea with blood and, occasionally, puppies with severe roundworm infections will actually vomit up worms.


Hookworms feed on large quantities of blood from the intestine which results in anaemia, particularly in puppies.

Weight Loss and Lethargy

Intestinal worms can damage the lining of the digestive tract and make it less able to absorb nutrients leading to malnutrition.

No Symptoms

It is important to note that some intestinal worm infections have no symptoms at all. Tapeworms rarely cause disease in dogs, so your precious pooch could be infected and you would not know. The only way to find out is by having your dog regularly examined by your vet.

Can Humans Get Worms from Dogs?

Diseases that are passed from animals to humans are called "zoonoses" and some canine intestinal worms are "zoonotic". Children are at more risk of becoming infected with canine intestinal worms because they play on the ground, put dirty objects in their mouths and sometimes eat dirt. Soil becomes contaminated with the eggs and larvae of intestinal worms when infected dogs pass faeces.

Dogs that are infected with intestinal worms pass eggs or larvae in their faeces which are able to infect humans after about two weeks in the soil. These eggs and larvae can survive for weeks and sometimes years in areas such as dog parks, playgrounds and backyards.

Accidentally ingesting fleas which are infected with flea tapeworm larvae can also lead to tapeworm infection in humans.

Can Humans Get Worms from Dogs Licking Them?

Unfortunately, yes. Your beloved pooch can transmit worm eggs as they lick your face. If they have been in recent contact with contaminated soil or faeces, and these eggs are accidentally ingested, this can lead to an infection. There are a few types of worms which can spread from dogs to humans - tapeworms, hookworms and roundworms. Hookworms can also enter the human body upon contact with contaminated soil from dog stools, where larvae can penetrate the skin, causing redness and itching.

To protect you and your family from worm infections:
  • Make sure everyone in your family washes their hands thoroughly with soap and water after outdoor activities and interacting with animals and before handling food
  • Keep lawns, play areas and gardens (particularly gardens that produce food) from being contaminated with dog faeces.
  • Pick up dog faeces and dispose of appropriately - never hose faeces into the ground as this causes contamination
  • Cover childrens' sandpits when not in use
  • Wear shoes outdoors
  • Treat pregnant female dogs for intestinal worms
  • Start puppies on intestinal worm treatment at 2 weeks of age
  • Ensure all pets are on an effective parasite control programme parasite control program which covers both intestinal worm and fleas
  • Have your pets regularly examined by your vet as some worm infections don't cause any signs of illness
man and girl washing hands

How to Treat Worms in Dogs

A typical worming schedule for dogs involves treating puppies every 2 weeks until 12 weeks of age, then once per month until 6 months of age and then every three months for life. However, this is only a general guideline and dogs that have a lot of outdoor exposure or access to raw meat or offal may need more frequent worming. Spirometra tapeworms need a higher dose of medication than other species of tapeworm in order to be successfully treated. Diagnosis and treatment of infection with this worm requires veterinary supervision. Always consult with your vet to determine the best intestinal worm program for your dog.

There is absolutely no evidence that home remedies such as garlic, pumpkin seeds and apple cider vinegar are effective and relying on these can lead to severe worm infestations in dogs, dangerous environmental contamination and increased risk for you and your family.

What is the Best Worming Tablet for Dogs

The only way to get rid of worms in dogs is to use an effective treatment, and the best type would be one that kills all common intestinal worms of dogs in a safe and effective manner. Luckily, there are many choices of intestinal dog worming treatments available in different forms such as tablets, chews and topical (spot on).

Common ingredients in these reliable worming treatments include milbemycin, praziquantel and pyrantel. These work by successfully targeting the worm’s nervous system or muscles, causing spasms and paralysis, and eventually death of the parasite. Worming tablets will start working immediately after being administered and worms may be present in faeces after 2-3 days.

Vet recommended worming tablets

How to Give a Dog a Worming Tablet

Worming tablets are available in either a chew or tablet form. Chewable tablets are flavoured and can be offered as a treat. Tablet forms can be given directly into their mouth or hidden in a piece of food if needed.

Tasty liquid treats and pastes could be helpful when administering tablets to fussy dogs!

What to Expect After Deworming Your Dog

Can Worming Make Dogs Sick?

Adverse reactions to worming tablets may occur in the form of gastrointestinal upsets, such as vomiting or diarrhoea. More severe reactions may involve respiratory distress (excessive panting), lethargy, weakness and convulsions.

If you suspect your dog has a negative response to their worming tablet, bring them in for veterinary attention and advice about their worming protocol in the future, and report the reaction to the manufacturer.

As the worms die, they may be passed out in the stool. This may be alarming to see but don’t worry, they will not cause further harm to your pet or infect your family.

Does Worming Cause Diarrhoea in Dogs?

Diarrhoea may be a side effect of worming. The adverse gastrointestinal effects are generally mild and transient. If the diarrhoea persists or you notice other symptoms, please bring them to your vet for assessment and treatment.

Can I Worm My Dog Twice in One Week?

If your dog has worms, treatment over consecutive days may be recommended. Always follow advice from your veterinarian. Generally, one dose at the appropriate dose will be sufficient.

Worming tablets have a high safety margin and doubling up may not lead to significant issues. However, there could be an increased risk of gastrointestinal side effects. These tend to be mild and most pets should recover quickly.

In conclusion

Intestinal worms can be a serious threat to the health and wellbeing of not only your beloved dogs, but also you and your family. The good news is that guarding against this danger is not difficult and only requires sticking to a vet approved parasite control program, regular vet visits to pick up any early warning signs and maintaining hygiene around your home.

Frequently Asked Questions

Do worms make dogs itch?

Worms do not usually make dogs itch. As mentioned earlier, it is rare for dogs with worms to present with an itchy bottom and more likely that anal gland issues are causing those symptoms.

Can you worm a pregnant dog?

It is recommended that pregnant dogs are wormed regularly prior to mating and during their pregnancy. An extra dose of worming 10 days before the pups are born is ideal to reduce risks of infection to the young and susceptible newborns. During lactation and nursing, the mother should be wormed every 3 weeks. Not all wormers are labelled as safe for pregnant and lactating dogs. Check our pregnant dog guide for which wormers are safe to use.

Can worms cause blood in the stool in dogs?

Worms can cause bloody diarrhoea as well as produce symptoms of poor body condition, debilitation and anaemia as they suck out blood and nutrients from inside the body. Ulceration on intestinal walls may be present, which will bleed and can result in dark, tarry faeces.

How do dogs get tapeworms besides fleas?

Dogs may become infected with tapeworm by eating offal or raw meat which could contain hydatid tapeworm larval cysts. Another method of transmission is by drinking contaminated water. Learn more about tapeworms in dogs.

Using a regular wormer that includes praziquantel as an active ingredient is an effective way to prevent tapeworm in your dog. Dogs with exposure to raw meat and who hunt may benefit from increased frequency of worming.

Further Reading

How Often Should I Worm My Dog

When To Worm A Pregnant Dog

Your Complete Guide to Fleas, Ticks and Worms

Which Flea and Worming Product Do I Need For My Dog?

New Puppy Guide


One Health Volume 17, December 2023, 100587: Canine gastrointestinal parasites perceptions, practices, and behaviours: A survey of dog owners in Australia. Luca Massetti, Rebecca J. Traub, Louise Rae, Vito Colella, Lara Marwedel, Phillip McDonagh, Anke Wiethoelter

L. Massetti, A. Wiethoelter, P. McDonagh, L. Rae, L. Marwedel, F. Beugnet, V. Colella, R.J. Traub. Faecal prevalence, distribution and risk factors associated with canine soil-transmitted helminths contaminating urban parks across Australia Int. J. Parasitol., 52 (2022), pp. 637-646, 10.1016/j.ijpara.2022.08.001