Gungahlin Vet Hospital

Worms and worm control

Worm parasites of dogs and cats can cause serious disease in pets and in hmans - ongoing and effective control is important

Products for worms (internal parasites)
While many products are widely available for worm control in dogs and cats, many do not cover all the parasites or are otherwise less reliable. Our recommendations are:



Why worm?

Nearly every time you visit the vet, you will be asked whether your pet’s worming is up to date and being given regularly. Is this just another way to sell you something and make money? Not at all.

Worms cause disease and suffering in dogs.
Worms are parasites, that is, creatures that live in and off another animal and return nothing to the host animal. Some worms, such as tapeworms (Cestodes) just absorb nutrients from the host’s gut through their cuticle (skin), and in practice the tiny reduction in nutrient available to the host is insignificant. Others, like hookworms (a Nematode worm) have mouth parts with sharp “teeth” and latch on to the lining of the gut and suck blood from the host. In large enough numbers, hookworms cause anaemia ((insufficient red blood cells and haemoglobin) leading to weakness and sometimes death. Other nematodes, such as roundworms, are large and cause malnutrition, particularly in puppies and kittens, leading to skinny young animals with fat bellies and poor hair coats, while whipworms (dogs only) cause diarrhoea with straining, mucus and sometimes blood. Heartworm of dogs causes heart failure with a chronic cough and weight loss, and, eventually, death.

Dog (and cat) worms can cause serious disease in people.
While the effects of worm on dogs and cats is important, many of these parasites are also a cause of serious problems in people. Although the risk may be relatively low, the effect can be devastating. People, especially children, who accidentally swallow the eggs of roundworms can develop disease of the liver, lungs and other organs called visceral larva migrans, and if a roundworm larva migrates to a human’s eye it can cause severe disease and blindness called ocular larva migrans. Hookworm larvae in the skin of humans (from walking barefoot on dog faeces contaminated soil) can cause a spidery tracery of red lines and itchiness due to cutaneous larva migrans. And, previously common in this part of Australia, humans who swallow the eggs of the Hydatid tapeworm from dog faeces develop Hydatid disease. They develop fluid filled cysts, sometimes many litres in capacity, filled with immature hydatid tapeworms, in various organs most especially the liver and lungs. Other tapeworms of dogs can cause cysts in the brain of humans. The dog heartworm can cause spots on the lungs of humans on X ray, although they seem not to cause disease.

People pick up these dog and cat parasites by:

  • Accidentally swallowing the eggs of worms, which come from dog and cat faeces, when handling dogs (touching, patting, cuddling, kissing; being licked by dogs), from the environment (worm eggs in soil, larvae on plants), while eating after touching a pet.
  • The immature stage of the cat parasite Toxoplasma may be present in raw or undercooked meat, and poor kitchen hygiene and cooking practices are an important source of human infection. The other source is eggs from cat faeces which may be present in garden soil, vegetable beds, sand pits etc
  • Bare skin (eg feet) on ground contaminated with dog faeces

The eggs of worm parasites can survive for a long time (sometimes years) and be dispersed by wind and flying insects (eg flies).

How do dogs and cats get infected?
Dog and cat parasites are extremely efficient at reproducing and spreading to a new host. Some cross the placenta before the puppy or kitten is born, some can cross through the mammary glands to suckling puppies and kittens. An environment contaminated by dog or cat faeces leads to a store of infection for animals entering that place, and these eggs can be taken up by insects, reptiles and amphibians, birds and small mammals and infect the dog or cat when hunting. A brain parasite of dogs in Brisbane and north is caught by eating snails. Livestock species, especially sheep, can be infested with the infectious stages of various parasites and dogs and cats (and humans) can be infected by eating undercooked or raw meat, especially offal (liver, lungs etc).

All puppies and kittens carry worm parasites when they come to their new homes with us, regardless of worming products given to the bitch or queen, or to the puppies and kittens, by the breeder or other source like pet shops. This is why worming puppies and kittens is so important and must be repeated many times while the animals are young.

All adult animals may be carrying worms and may be reinfected from their environment or food. This is why it is important to continue to worm adult dogs and cats throughout their lives. Your vet will give specific advice based on an assessment of your pet’s risk of getting or being infected , and the risk to the humans with which they live. For example, worming may be recommended more frequently in a house with small children or where grandchildren visit. But consider also whether you walk your dog near children’s playgrounds, schools etc.

How often should I worm my pet?

The following are Gungahlin Veterinary Hospital’s recommendations for worming dogs and cats:

  • Puppies and kittens should be wormed about every two weeks from birth to three months of age, unless a specific type of wormer (Interceptor, Milbemax) is used in puppies in which case monthly worming is OK.
  • Puppies should be wormed monthly for the first twelve months of their lives, because of the high chance they are carrying and passing worms and eggs. Kittens should be wormed monthly till 6 months.
  • Dogs (>12 months) and cats (>6 months) should be wormed for intestinal worms at least every three months throughout their lives. Dogs should receive a heartworm preventative product according to packet directions from at least three months of age.
  • Dogs who live with or regularly mix with small children should be wormed monthly to reduce risks of infection of the children.

What products should I use?
While many products are widely available for worm control in dogs and cats, many do not cover all the parasites or are otherwise less reliable. Our recommendations are:





How else can I protect my pets and my family?

Practice good hygiene.

  • Clean up dog faeces at least every two days and dispose of in garbage, or a specific dog faeces composter.
  • Wash hands after touching dogs
  • Don’t eat while playing with dogs (or cats)
  • Don’t let dogs lick you (especially on the face, or on cuts, scratches, grazes or sores)
  • Don’t kiss dogs or cats

Remove faeces from cat litter trays regularly. Clean litter trays completely about weekly, but don’t use disinfectant, rather rinse with very hot water. Pregnant women and the immunosuppressed (AIDs, chemotherapy, immune mediated disease) should avoid cleaning litter trays, or at least where rubber gloves.

Don’t feed dogs and cats raw meat or other body parts, (except raw bones); rather feed a complete pet food which  is sterile because it has been heat extruded (dry food) or coked in the can (canned food).

Prevent dogs and cats wandering to prevent them hunting or eating raw or contaminated food, carcases and waste products.

All the recommended products are avaiable from Gungahlin Veterinary Hospital, or from our on-line shop. We can give personal advice at the hospital.