Parasites are a common and important cause of disease in cats and dogs. Although most people know about external parasites like fleas and ticks, many do not realize that intestinal parasites can also cause significant health problems.

Intestinal parasites are parasites that live inside the host animal’s gastrointestinal tract (the stomach and intestines). Examples include worms (roundworms, whipworms, hookworms, tapeworms) and protozoa (giardia and coccidia).

Dogs and cats can contract intestinal parasites via different routes. Parasites are usually transmitted when an animal inadvertently ingests parasite eggs or spores in contaminated soil, water, faeces or food. In the case of tapeworms, they can also be transmitted when a dog eats an infected flea. Puppies, on the other hand, usually get intestinal parasites from their mother. Transmission can occur while the puppies are still in the womb or during nursing.

Intestinal parasites can cause malnutrition, weight loss, vomiting, diarrhoea and anaemia. Besides making our pets sick, many of these parasites can also affect people.


What are the symptoms of intestinal parasites?

While external parasites like fleas and ticks are easy to see, intestinal parasites are harder to see because they live inside your pet and pass microscopic eggs or spores in your pet’s stool that are too small to be seen without a microscope. Tapeworms are one exception, they shed segments that resemble grains of rice and are typically seen in your pet’s stool or around their rectum. Roundworms are another exception since they may occasionally be seen in your pet’s vomit or stool. Even though you might not be able to see intestinal parasites, it is important to remember that prevention is much better than cure. Besides being hard to detect, many animals infected with intestinal parasites may have very minimal or no symptoms at all of the infection. Animals that do show symptoms of an infection may present very non-specific signs that could mean that a diagnosis of infection is missed.


The most common signs and symptoms of intestinal parasites are:

  • Scooting (your pet dragging their hindquarters across the floor)
  • Vomiting
  • Diarrhoea
  • Swollen abdomen
  • Weight loss
  • Occasionally coughing
  • Loss of appetite
  • Dehydration
  • Pale gums

Since dogs infected with intestinal parasites can exhibit no symptoms or subtle symptoms that can be easily overlooked, the best way to ensure that your dog is parasite-free is to take him to a vet for a faecal test. A faecal test allows your veterinarian to diagnose intestinal parasites by looking for microscopic eggs or spores in your pet’s stool.


How can you prevent intestinal parasites?

While the thought that your pet may have intestinal parasites may give you the heebie-jeebies, intestinal parasites are very treatable and even easier to prevent. Our vets recommend the following courses of preventative treatments for cats and dogs:

Puppies and kittens – worming treatment should be given at 2, 4, 8 and 12 weeks of age. Between the ages of 3-12 months, your pet should be wormed every 3 months (or as recommended by your vet).

Adult cats and dogs – worming treatments should be given every 3-4 months or as recommended by your vet. If your pet spends time outdoors, treatment may need to be more frequent.

If you are bringing a new pet into your home, it’s important to have them checked by your veterinarian so that they do not expose your other pets or family to parasites. Although intestinal parasites are treatable, remember that the best way to protect your pets against parasites is to keep them on parasite preventatives.

If you have any questions or concerns, speak to your vet.