When 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 kids 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 damage to the retina (the part at the back of the eye that senses light).
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.
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 like to put things in their mouths and don't often wash their hands.
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.
Toxocariasis usually happens in young children ages 2 to 7, but can happen at any age. It can't be spread from person to person.
To help prevent kids from being exposed to toxocariasis:
- keep them away from areas where dogs or cats play
- teach your kids to wash their hands often, especially after playing with a pet dog or cat (wash a toddler's hands yourself)
- discourage toddlers from putting dirty hands in their mouth
- keep pets away from the sandbox and cover the sandbox when it's not being used
- take household pets to the veterinarian to be dewormed, especially puppies younger than 6 months old
- make sure your kids don't accidentally eat dirt or soil
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 toxocariasis, doctors sometimes also prescribe steroids or might refer a person to a specialist (like an ophthalmologist if the eye is involved).
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:
- cough or wheezing
- abdominal pain
- poor appetite
- vision problems
Reviewed by: Rupal Christine Gupta, MD
Date reviewed: August 2014
|Centers for Disease Control and Prevention (CDC) The CDC (the national public health institute of the United States) promotes health and quality of life by preventing and controlling disease, injury, and disability.|
|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.|
|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.|
|Toxoplasmosis Toxoplasmosis is an infection that passes from animals to humans, sometimes without causing any symptoms. Learn more about this infection in this article for parents.|
|Are Certain Pets Better Than Others, Especially for Young Kids? Find out what the experts have to say.|
|Cat Scratch Disease Cat scratch disease is an infection that causes swelling of the lymph nodes after a cat scratch or bite. Learn about signs and symptoms, prevention, treatment, and more.|
|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.|
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
© 1995-2016 KidsHealth® All rights reserved.
Images provided by iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com