white puppy walking through grass

Intestinal Worms In Dogs: Causes, Symptoms and Treatment

LAST UPDATED October 2023

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

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:
• Understand the ways your dog can become infected with worms
• Recognise the symptoms of worm infestations
• Know which parasite control products are the most effective.

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

roundworms

Roundworms

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

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.

Whipworm

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

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

worms

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.

Anaemia

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.

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 Get Rid of Worms in Dogs

The only way to get rid of worms in dogs is to use an effective treatment 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).

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.

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.

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

References:

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