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Intestinal Parasites

Intestinal parasites are life forms that live in the intestinal tract of other living geings (the host). The parasites may injur the lining of the intestinal tract as they sap the nutrients from the host's tissues or intestinal contents. This weakens the host from tissue injury, diarrhea, blood loss, loss of vital nutrients, dehydration and shock. If the parasite is allowed to flourish without interruption, the host may become weakened enough to die.

Parasites are diagnosed through examination of your pet's feces and laboratory tests.

Common intestinal parasties found in your pet may be:

Ascarasis (roundworm infection)

Roundworms are the most common intestinal parasite of dogs and cats. Pets become infected by swallowing roundworm eggs or larvae found in contaminated soil or feces or by eating infected rodants, birds and certain insects. Puppies and kittens are commonly infected by the mother while still in the uterus. Swallowed larvae travel through the body to the intestine, where they develop into mature worms. There, adult females deposit eggs, which pass with the stool and develop into infected larvae.

Human infection with roundworm larvae (not adults) is possible but does not occur frequently if good hygiene is practiced, because eating contaminated stoll or soil is necessary for infection.

Ancylostomiasis (hookworm infection)

Hookworms are relatively common intestinal parasites of dogs, cats and other animals. Adult worms live in the small intestine, and their eggs pass out with the stool. Diagnosis is by identifying the eggs during microscopic examination of the stool.

Animals become infected with hookworms by eating infective eggs or larvae, penetration of the skin or footpads by larvae, or transmission of larvae from the mothing while the fetus is still in the uterus. The time from consumption of infective larvae to the appearence of eggs in the stool is 15 to 26 days.

Hookworms are one of the most serious intestinal parasites, as they feed on the blood of their host animals and can cause severe anemia. In young, weak, or malnourished animals, hookworms can cause sudden collapse and death. Older, more resistant dogs may suffer a slow, progressive, wasting disease. Weight loss, diarrhea, and tarry or bloody stool frequently occur in animals with hookworms.

Hookworm larvae can penetrate human skin and cause skin disorders known as cutaneous larval migrans or creeping eruption. This infection is not common, but anyone who develops a skin rash after being in contact with a pet with hookworms should consult a physician.

Trichuriasis (whipworm infection)

The whipworm is a small, thin worm that lives in the large intestine and cecum. The cecumis a blind pouch located between the small and large intestine; it resembles the human appendix.

The whipworm gets it name from its body shape. Its body is very delicate and its tail tapers into a narrow whip-like structure. It is difficult to in the stool because of its very small size.

Whipworms can cause diarrhea, bloody feces and poor general health. Massive rectal bleeding occasionally occurs. Diagnosis is byu micrscopic examination of the feces. Sometimes several samples must be examined before worm eggs are found. It takes about 3 - 4 months after infection until eggs are passed in an infected pet's stool.

Cestodiasis (tapeworm infection)

The tapeworm ia a parasite found in the intestines of dogs and cats. It consists of a head and a long flat body made up of segments. Segments are passed in the animal's feces, leaving the head still attached to the animal's intestinal lining, where it produces new segments.

Tapeworm infection may cause noticeable illness in your pet, or it may produce digestive upset, poor appetite, poor haircoat and skin, weight loss and vague signs of abdominal discomfort.

Tapeworm infection is diagnosed by finding the segments in your pets feces, in its bed, or clinging to the hair around the anus. The eggs may or may not be found on a microscopic examination of the feces. When first passed, segments are yellowish to white and about 1/4 inch long, and may expand and contract. When dry, the segments resemble cucumber seeds or grains of rice.

Tapeworms are not passed directly from pet to pet but require an intermediate host in which to develop. Common intermediate hosts are fleas and small animals, such as mice, rats, squirrels and rabbits. Fish are the intermediate host for one type of tapeworm.

Coccidiosis(protozoan infection)

Coccidiosis is a parasitic disease of the intestinal tract caused by microscopic organisms called Coccidia. The disease spreads from one animal to another by contact with infected feces. Itis most severe in young or weak animals and often causes bloody diarrhea. this disease is not a threat to people.


Giardiosis is an intestinal disease of people, dogs, cats and other animals. It is caused by a microorganism called Giardia, which is swallowed when the animals eats contaminated stool, food, or water. Giardia principally infects the upper small intestine. Infected individuals pass the infective cysts in their stool, and the cycle begins again.

Diagnosis may be difficult; therefore, repeated microscopic examinations of multiple stool samples are often needed to find the cysts.

The most common sign of infection is persistent diarrhea, with pale, greasy, and occasionally blood-tinged stool. Giardia prevents proper absorption of nutrients, damages the delicate intestinal lining and interferes with digestion.

Giardia is a relatively common intestinal parasite in people. Good personal hygiene should be practiced in homes where Giardiosis has been diagnosed in a pet. Your pet's stool should be cleaned up and properly disposed of. Children should not be allowed to handle the stool.

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