Worms, Your Dog and You

Worms are a worry. Regular worming is essential (every 3 months) to protect your dog against worms, and to protect your family. People can also be infected by worms, by accidentally swallowing the worm eggs that are passed in dogs droppings. Children are most at risk because of the close contact with their pets.


Hookworms are the most destructive of the intestinal worms because they burrow into the pet’s intestinal wall and suck blood. Signs include soft tar-like faeces, diarhhoea (usually with blood staining), dehydration, pale gums (anaemia), weakness and death if puppies are infected with large numbers of worms. Hookworms are quite small so it is not common to see hookworms in the animal's droppings after proper treatment.

Infection can take place by eating worm eggs from the ground, larvae present in the environment can penetrate the skin of the abdomen or feet, or larvae can pass out in the mother’s milk to suckling puppies. The cycle from adult worms laying eggs, the eggs hatching into infective larvae and maturing into new adult worms takes only 2 – 3 weeks.

Hookworm larvae can also penetrate the skin of humans, causing intense itching. Always wear gloves when cleaning up after your dog.


Roundworms are the most common of the intestinal worms and are long (up to 18cm), white and cylindrical, and can be easily seen in dog droppings. Unborn puppies are usually infected with roundworm larvae via the mother's placenta and will have adult worms in their intestines within 2 weeks of birth. Infection can also occur by eating infected rodents, droppings of other pets and contaminated soil. Roundworm eggs are quite sticky and attach to dog hair, feeding bowls and bedding and, unless you worm your dog regularly, constant reinfection will occur.

Signs of infection include ill thrift, a 'pot-belly' appearance, diarrhoea, vomiting (sometimes including whole worms) and coughing. Heavy infections can cause death, especially in puppies, due to intestinal obstruction.

Roundworm larvae can also infect people, especially children, by accidentally swallowing infective eggs that get on their hands after playing with the dog or from the soil. Once infected migrating larvae can cause damage to the liver, eyes and nervous system of humans. This disease is called Visceral Larva Migrans (VLM).


Whipworm infection occurs when a pet eats whipworm eggs. After the eggs hatch the larvae move to the lower bowel where the mature worms can survive for up to a year. These mature worms produce eggs that are passed in the pet’s droppings and are able to survive in the soil for a long time making reinfection common, especially in dogs confined to small outdoor yards.

Symptoms are mostly chronic, including weight loss, abdominal pain and intermittent diarrhoea (occaisonally with fresh blood).

Flea Tapeworms

The tapeworm Dipylidium caninum is the most common of the tapeworms and is spread by fleas, an intermediate host. Part of the tapeworm's lifecycle develops in fleas and when a dog eats an infected flea (mostly during grooming) the tapeworm develops in the animal's intestine.

Infection is not usually serious and people are rarely infected. The most common sign is your dog 'scooting' or dragging its bottom along the ground due to irritation of tapeworm segments emerging from the dog's anus. The segments look like rice grains and can be easily seen wriggling around the dog's bottom or on it's fur.

Hydatid Tapeworms

The hydatid tapeworm, Echinococcus granulosus, is a serious risk to human health, especially in country areas.

An intermediate host is required for the lifecycle of the worm to be completed. These are grazing animals, such as sheep, cows or kangaroos, and they pick up worm eggs from dog droppings in the pasture, which then form cysts in their body organs (such as the lungs and liver). Dogs are infected by eating raw meat and offal (body organs) infected with cysts but suffer no ill effects.

People, also an intermediate host like sheep and cows, become infected by swallowing eggs found in dog faeces. After the eggs hatch the larvae pass through the body forming cysts in organs such as the liver, lungs, brain and kidneys and can be fatal.

Treatment of worms

Worms can be eliminated with common worming medications that are available from your veterinarian. Be sure to choose a medication that will treat all four worms that your pup can be affected by.

However, if your pup is already unwell, it may need other medication to control any diarrhoea that is present and possibly even a blood transfusion. Your vet's advice should be sought if your pup is weak and lethargic or if it is vomiting and you suspect it has a worm infestation.

Prevention of worms

Preventing worm infestations is a very important matter. Puppies under three months of age should be wormed every two weeks from two weeks of age onwards. There are various worming suspensions that are ideal for puppies of this young age.

Once the pup reaches three months of age is it advisable to worm it every month until it is six months old and thereafter it should be wormed every three months.

Many owners place their dogs onto a monthly heartworm medication that also contains an intestinal worming medication. This is a good idea as the dog is wormed for the common worms every month. However, the monthly heartworm/intestinal worm combination does not treat all intestinal worms e.g. tapeworms. Therefore, worming an adult dog that is on such a medication with a tapewormer should still be done every three months (or 6 weeks in hydatid areas).

Other tips on worm prevention

  • Children (and adults) must wash their hands after playing with their pet
  • Wash your hands after playing and working in your yard
  • Avoid dogs licking you and your family about the face
  • Remove dog droppings from your yard and litter trays
  • Clean kennels and sleeping areas regularly
  • Concrete runs are best
  • Worm any cats/other pets in the household as well
  • Control fleas on your pets
  • Don't feed your dog raw meat and sheep offal

- Last updated 16 November 2012

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