Pet Columns, Office of Public Engagement, College of Veterinary Medicine at the University of Illinois at Urbana-Champaign

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Warning: Worms Can Hurt You and Your Pet!

Pet Column for the week of June 4, 2001

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Services - Public Health

Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
Jennifer Stone
Information Specialist

That cute little potbelly that many puppies seem to have could be caused by worms! Most dogs and cats acquire some type of intestinal parasite during their lifetime, and these worms can not only be annoying, but can cause debilitating medical problems, especially in young animals. It is important to remove these parasites for the sake of your pet, and also because humans can become infected.

Roundworms are probably the most common intestinal parasite that infects companion animals. According to Dr. Allan Paul, a veterinary parasitologist at the University of Illinois College of Veterinary Medicine in Urbana, "Most parasite eggs require a minimum temperature in order to develop into an actively infectious state. For this reason, they are most likely to be spread during the spring and summer."

Roundworm eggs are excreted in the feces in dogs and cats. They are spread when animals come in contact with the feces or soil. These worms can also be transmitted across the placenta to puppies before they are born and spread from mother cats to kittens through infected milk.

Once they develop into their adult form, roundworms live in the intestine and feed off the food the dog or cat has eaten. They are very prolific. One female can lay up to 200,000 eggs per day. This means that a large number of worms can develop in a short period.

Infestation can cause diarrhea, vomiting, and the characteristic potbelly seen in many puppies. A rough hair coat and generally unhealthy appearance are other signs. These worms are usually not a serious problem for adult animals, but can be life-threatening to puppies and kittens that may experience severe dehydration as a result of vomiting and diarrhea.

Hookworms and whipworms are other common parasites in dogs and cats. Instead of feeding off digesting material in the intestine, these parasites attach to the intestinal lining and feed by sucking the blood of the infected animal. A heavy infestation of either of these parasites can cause severe anemia.

Hookworms are more common than whipworms. Hookworms feed at several places in the intestine each day, injecting an anti-coagulant that prevents clotting. This means that after the hookworm detaches from the intestinal wall, that spot continues to bleed, which can cause a black, tarry-looking stool. Hookworms can be transmitted through oral ingestion of eggs in fecal material and also by penetrating the skin directly.

Your veterinarian can diagnose roundworms, hookworms, and whipworms by doing a fecal examination in which the eggs of the worm are identified. The worms can easily be removed by the administration of a dewormer prescribed by your veterinarian.

It is important to treat intestinal parasites in your pet because they can be transmitted to humans. Roundworms and hookworms do not mature in the intestine in human beings. Instead, they remain in an immature larval state and migrate throughout the tissues of the body. They can cause liver and lung damage, skin rashes, and even blindness and permanent neurological damage. Children are most at risk because they may play in infested areas and may ingest infected material. The best way to prevent infection is to make sure your pets are parasite free and your children always clean up properly after playing outside.

To prevent problems with intestinal parasites for your pet and for you, consult your local veterinarian on deworming and parasite control.