Visceral Larva Migrans: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Visceral Larva Migrans?
Many cases are first treated by a primary care doctor. A gastroenterologist often helps when the belly or liver is involved. If the eyes are affected, an ophthalmologist joins the care team. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Visceral larva migrans is an infection caused by tiny worm larvae, which are baby worms. People pick up the parasite by swallowing its eggs, often from soil. The worms are called Toxocara and normally live in dogs and cats. In people, the larvae cannot grow into adults, so they wander through organs like the liver, lungs, and eyes. Most infections cause no symptoms, but some people get sick and need treatment.
Symptoms
Many people never feel sick. When symptoms do appear, they often include fever, tiredness, coughing, wheezing, belly pain, and a poor appetite. In rare cases, the larvae reach the eye and can harm vision, a condition called ocular toxocariasis. Symptoms can last for months because the larvae stay alive in the body.
Causes and who gets it
Dogs and cats that carry Toxocara pass eggs in their stool. The eggs end up in sand, soil, playgrounds, and parks, where they can survive for years. People swallow the eggs when they put dirty hands or toys in their mouths. Young children are at highest risk because they play in dirt and often forget to wash their hands. Owners of puppies or kittens also face a higher risk.
How doctors diagnose it
Doctors start by asking about symptoms and exposure to dogs, cats, or soil. A blood test can look for antibodies, proteins the immune system makes to fight the parasite. Doctors may also order an ultrasound or CT scan to check the organs in the belly. If the eye is affected, an eye doctor may examine it for larvae.
Treatment
Treatment depends on how sick the person is. People with mild or no symptoms often need no medicine. When symptoms are bothersome, doctors may prescribe an antiparasitic drug, sometimes with a steroid to calm inflammation. Eye infections need care from an eye specialist, and treatment does not always restore damaged vision.
When to see a doctor
Anyone with a lasting fever, belly pain, cough, or wheezing should see a doctor. Sudden changes in vision need prompt medical attention, because eye damage from this parasite can become permanent.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either can be a good first stop, ordering tests, prescribing antiparasitic medicine, and referring severe cases to the right specialist.
Common questions
Can visceral larva migrans spread from person to person?
No. The parasite cannot pass directly between people. It only spreads when someone swallows the eggs from soil or contaminated objects.
Is this infection common?
Exposure to Toxocara is fairly common in the United States, and blood tests show many people have been exposed. Most of those people never develop symptoms. Serious illness is uncommon.
How can I prevent it?
Wash hands after touching soil, sand, or pets, and teach children to do the same. Keep pets dewormed, and cover sandboxes when not in use. Wash fruits and vegetables grown in gardens that pets can reach.
Does the infection go away on its own?
In many people, symptoms fade without treatment because the larvae eventually die. This can take months or even years. Anyone with ongoing symptoms should still see a doctor rather than wait it out.
Sources
- Centers for Disease Control and Prevention - About Toxocariasis | Toxocariasis
- MedlinePlus Medical Encyclopedia - Visceral larva migrans
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
