What is Toxocariasis

Toxocariasis is an infection caused by parasitic roundworms. The infection starts in the intestines and can spread to other parts of the body. The infection usually does not cause problems, but it can lead to vision problems if it spreads to the eyes. Most people with this condition never get sick or have symptoms.

What are the causes?

This condition is caused by roundworms of the Toxocara family. The roundworms are commonly found in the intestines of dogs and cats. Dogs and cats with roundworms may shed roundworm eggs in their feces. People can get this condition if they:

• Do not properly wash their hands after touching cat or dog feces, dirt, or sand that has been contaminated by roundworm eggs.
• Eat food or drink water that has been contaminated with roundworm eggs.
• Eat dirt or sand that has been contaminated with roundworm eggs.

What increases the risk?

Young children are more likely to have this condition because they are more likely to put things in their mouth or touch their mouth. People who own pets, especially cats or dogs, are also more likely to have this condition.

What are the signs or symptoms?

Most people do not have any symptoms and may not know that they have been infected.

If symptoms develop, they may include:

• Fever.
• Coughing.
• Noisy breathing (wheezing).
• Weakness.
• Swollen glands.
• Poor appetite.
• Rash.
• Abdominal pain.
• Eye swelling.
• Vision loss.

How is this diagnosed?

This condition may be diagnosed based on:

• Your medical history.
• A physical exam.
• Blood tests.
• Imaging tests, such as a chest X-ray, ultrasound, or CT scan.

How is this treated?

Treatment depends on the severity of the condition. If the condition is mild, no treatment may be needed. If the condition is severe or if symptoms do not go away on their own, treatment may include:

• Medicines. These may be given to:
  • Kill the roundworms (antiparasitics).
  • Help with eye swelling (steroids).
• Surgery to prevent eye damage.

Follow these instructions at home:

• Take over-the-counter and prescription medicines only as told by your health care provider.
• Keep all follow-up visits as told by your health care provider. This is important.

How is this prevented?

• Wash your hands well with soap and water after playing with animals and after outdoor activities.
• Wash your hands before you eat.
• Have your veterinarian treat your pets regularly for worms.
• Clean your pet’s living area at least once each week. Feces should be either buried or bagged and thrown away in the trash.
• Do not allow children to play in areas where there are animal feces. Check for animal feces in outdoor areas where children play, such as playgrounds or sandboxes.

Contact a health care provider if:

• You continue to have symptoms after treatment.
• You develop new symptoms.
• The condition returns after treatment.

Get help right away if:

• You develop vision problems.

Summary

• Toxocariasis is an infection caused by parasitic roundworms that are often found in the intestines of dogs and cats. The animals may shed roundworm eggs in their feces.
• People can get this condition if they eat food or drink water that has been contaminated with roundworm eggs.
• The infection usually does not cause problems, but it can lead to vision problems if it spreads to the eyes.
• No treatment may be needed for a mild infection. If the condition is severe, or if symptoms do not go away on their own, treatment may include medicine to kill the roundworms (antiparasitics).