Internal parasites (or “worms”) are worm-like organisms that infect areas of the body and feed off of the host’s nutrients or blood. They can cause diseases in our pets and some can infect people. Contrary to previous beliefs, a recent study in Calgary suggests that the incidence of internal parasites (especially roundworms and giardia) here is similar to that of warmer climates.

Types of parasites:

  • Roundworms: These parasites are very common in puppies and kittens. Animals with high numbers of these parasites have a typical “potbellied” appearance. Roundworms can spread through infected feces or soil as well as from the mother to her offspring. Roundworm larvae can travel and encyst throughout the body. This is why multiple dewormings are critical to eradicating roundworm infections. Roundworm eggs can last in the environment for years and are infectious to people as well as dogs and cats.
  • Hookworms: These parasites attach to the intestinal lining and suck blood. They can cause severe blood loss in young puppies. Hookworms are mainly spread through soil contaminated with feces. The larvae may be ingested or can also penetrate through the skin. Hookworms can infect humans and cause a skin condition called cutaneous larval migrans.
  • Whipworms: Whipworms are a parasite that live in the large intestine. They cause bloody diarrhea if infected with large numbers of worms. Whipworm infestations can also mimic another serious disease called Addisons. Infection is through soil contaminated with feces. Eggs can live in the soil for years.
  • Tapeworms: Tapeworms are segmented parasites that require an “intermediate host” and cannot spread directly from cat to cat or dog to dog. Most commonly, the intermediate host is a flea or a rodent although other animal species are also possible intermediate hosts. The host is ingested by a dog or cat to cause infection. Tapeworm segments in the stool look like rice granules. The worm itself can be 6inches or longer. Because fleas act as an intermediate host, flea control in addition to deworming is very important.
  • Giardia: Giardia (also called Beaver Fever) is a parasite typically contracted through rivers, streams and contaminated puddles (ie. At the dog park). Giardia causes chronic or intermittent diarrhea and occasionally vomiting, lethargy and reduced appetite. It can infect dogs, cats and humans and can be transmitted from pets to humans through infected feces.

Testing for internal parasites often involves a sample of feces for a “fecal floatation” test. The fecal float test separates parasite eggs from the rest of the stool. Since most parasites only shed their eggs intermittently and only in the adult stage, a negative float test doesn’t necessarily prove that there is no infection. But the float is useful to identify which parasite may be causing disease. Giardia has a specific fecal snap test that is very accurate.

Routine deworming is important to control parasite infections in dogs and cats. Even animals that are exclusively indoors (such as indoor only cats) have been shown to have internal parasites, possibly from fleas/insects or previously encysted worms. Many parasites are ingested simply by routine grooming when dogs and cats lick their feet and body. Some animals will show symptoms of parasite infections such as diarrhea, vomiting and weight loss. However, most animals will not show any symptoms.

Since many parasite infections are transmittable to people, controlling parasites becomes even more important. Children are especially susceptible as they tend to play in the dirt and are less concerned about hygiene. It is important to clean your pet’s bathroom area regularly and remove feces. Regular deworming is important to keep your pet free of parasites and schedules vary depending on your pet’s lifestyle.

Please discuss the best schedule for your pet with one of our veterinarians.