Toxocariasis

Toxocariasis

Lea este articulo en EspanolWhen common parasites of dogs and cats infect humans, the illness is called toxocariasis (or visceral larva migrans). Toxocariasis usually affects kids under age 10. Especially at risk are those who like to put things in their mouths, or those whose families have pet dogs or cats.

Signs and Symptoms

Many kids won't have symptoms, but if they do, they can include fever, cough or wheezing, abdominal pain, enlarged liver or spleen, poor appetite, a rash that sometimes looks like hives, and enlarged lymph nodes ("swollen glands").

Toxocariasis also may affect the eyes, causing decreased vision, swelling around the eyes, or a cross-eyed appearance. Untreated toxocariasis can cause retinal damage and decreased vision.

Most cases go undiagnosed and do not cause problems. Some toxocariasis cases are diagnosed during a routine eye exam or an X-ray study done for some other reason.

Transmission

Toxocariasis is an infection caused by the larvae of parasitic worms — Toxocara canis and Toxocara cati — that usually live in the intestines of dogs and cats. Eggs from the worms pass into the feces of dogs and cats and can contaminate pet areas around the home where kids play. The eggs can be swallowed by children, especially those who:

After entering the body, the eggs hatch into larvae that penetrate through walls of the digestive tract and may migrate to a child's liver, lungs, eyes, and elsewhere.

Experts in the United States estimate that about 20% of dogs pass Toxocara eggs into their stool. In Great Britain, 24% of soil samples taken from public parks contained the eggs. Toxocariasis cannot be spread from person to person.

Prevention

To help prevent kids from being exposed to toxocariasis:

Diagnosis and Treatment

A doctor can usually diagnose a case of toxocariasis by physical exam and blood tests. Doctors may not prescribe any medication to treat a child with mild symptoms. Severe toxocariasis involving the lungs, eye, or other important organs may be treated with antiparasitic drugs to kill the larvae. For severe lung toxocariasis, doctors sometimes also prescribe anti-inflammatory drugs.

A child with severe toxocariasis should be given medicine as prescribed by your doctor. Prevent reinfection by deworming your pets and keeping kids away from areas where pets defecate (poop). Remind your kids to wash their hands often during the day, especially after playing with pets.

When to Call the Doctor

Call your doctor if your child has any of the symptoms of toxocariasis, including:

Reviewed by: Joel Klein, MD
Date reviewed: September 2011





Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.

© 1995-2014 The Nemours Foundation/KidsHealth. All rights reserved.





Bookmark and Share

Related Resources
OrganizationCenters for Disease Control and Prevention (CDC) The mission of the CDC is to promote health and quality of life by preventing and controlling disease, injury, and disability. Call: (800) CDC-INFO
Related Articles
Why Do I Need to Wash My Hands? Washing your hands is the best way to stop germs from spreading. Learn all about the best way to wash your hands in this article for kids.
Why Is Hand Washing So Important? Did you know that proper hand washing is the best way to keep from getting sick? Here's how to teach this all-important habit to your kids.
Infections That Pets Carry Kids can benefit from the companionship, affection, and relationships they share with pets. But it's important to know how to protect your family from infections carried by pets and other animals.
Your Child's Habits Nail biting, hair twirling, thumb sucking, and nose picking - these childhood habits are common. Here's how to deal with them.
Pinworm Pinworm is an intestinal infection caused by tiny parasitic worms. But pinworms don't cause any harm (just itching), and it won't take long to get rid of them.
Are Certain Pets Better Than Others, Especially for Young Kids? Find out what the experts have to say.
Pets and Your Health Like people, pets can carry infections - and some of these can be transmitted to people. Find out how you and your pet can stay infection free.
Hand Washing Did you know that the most important thing you can do to keep from getting sick is to wash your hands? If you don't wash your hands frequently, you can pick up germs from other sources and then infect yourself.
iGrow iGrow
Sign up for our parent enewsletter