Vet Safety 2025: Roundworms in Humans—How to Spot, Prevent, and Protect Your Family 🧼🧠

Roundworms are one of the most common parasites in pets—but what many people don’t realize is that they can also infect humans. In 2025, human cases of roundworm infection, especially in children, remain a real and preventable threat 🐾🧬.

As Dr Duncan Houston, I want to provide a clear, up-to-date explanation of how human infection happens, what symptoms look like, and the smart, simple ways to protect your household 🏡🧤.

🦠 What Is a Roundworm?

Roundworms are intestinal parasites found in dogs and cats. The two species of concern for humans are:

• Toxocara canis – the dog roundworm
• Toxocara cati – the cat roundworm

These worms have a fascinating—but dangerous—life cycle. After pets shed their eggs in feces, the eggs need to mature for about a month in soil before becoming infective. This means fresh feces are not a risk, but soil that’s been contaminated for a few weeks is ⚠️.

📊 How Common Is Human Infection?

• 🧫 Up to 20% of U.S. playground soil samples are contaminated with roundworm eggs
• 🧬 Approximately 14% of the U.S. population has been exposed to roundworms (based on antibody testing)
• 👦 Most infections occur in people under the age of 20, with young children at highest risk

Children are more likely to put dirty objects in their mouths or play in soil or sandboxes that may be contaminated, making them especially vulnerable 👶🪣.

🔍 What Happens During Infection?

When a human ingests roundworm eggs (usually through soil), the larvae hatch and begin to migrate throughout the body—getting lost because they’re in the wrong host. This migration causes inflammation and damage 🧠🩸.

🧬 There are three main forms of human toxocariasis:

1. Covert Toxocariasis

• 🥵 Mild symptoms: fever, fatigue, abdominal discomfort, headache, sleep disturbance
• 🧪 Usually self-resolving with minor inflammation

2. Visceral Larva Migrans (VLM)

• 🔥 More intense symptoms due to large numbers of larvae
• 💥 Severe inflammation of internal organs: liver, lungs, brain, etc.
• ⚠️ Can be fatal in rare cases
• 👶 Mostly affects children aged 1–4

3. Ocular Larva Migrans (OLM)

• 👁️ Larvae get misdirected to the eye
• 🔬 Causes intense inflammation, vision loss, or blindness
• 📈 Approximately 1,000 U.S. cases/year, 700 with permanent vision loss
• 👦 Usually affects children aged 7–8

Unfortunately, once roundworm larvae reach the eye or brain, the damage is often permanent. Prevention is absolutely essential 👀🛡️.

💡 How Do People Get Infected?

• 🪣 Playing in contaminated soil or sandboxes
• 👄 Putting dirty hands or toys in the mouth
• 🥩 Eating undercooked meat
• 🐕 Contact with dirty pet fur (rare, low risk)

One study found that 50% of dogs had roundworm eggs on their fur—but only about one egg per dog, and only 4% were infective. Still, good hygiene is key 🧼🐶.

🚫 Don’t Rely on Appearance

You can’t tell if soil is contaminated just by looking. Roundworm eggs are microscopic and can remain infectious in soil for years. Sandboxes, lawns, playgrounds, and dog parks are all potential hotspots ⚠️🪴.

🧼 How to Prevent Infection

1. 🧴 Wash Hands Often

• 👐 Before eating or preparing food
• 🚿 After playing outside or handling pets

2. 🐾 Deworm Pets Regularly

• 🧑‍⚕️ Follow your vet’s deworming schedule, especially for puppies and kittens
• 📅 Monthly preventives are widely available and effective

3. 🪣 Cover Sandboxes

• 🛡️ Prevent outdoor cats from using it as a litter box

4. 🧹 Clean Up Pet Waste

• 🚮 Dispose of feces in your yard daily
• 🏞️ Follow local laws in public parks and walkways

5. 🍽️ Cook Meat Properly

• 🥩 Especially pork, lamb, and game meat

6. 🧼 Teach Kids Not to Eat Dirt or Put Dirty Items in Their Mouth

• 👶 Supervise young children outdoors

📲 Ask A Vet: We’re Here to Help

If you’re concerned about roundworms in your pet or household, talk to a licensed veterinarian through AskAVet.com or the Ask A Vet app. We can guide you through prevention, deworming, and safe play practices 📱🐾.

✅ Final Thoughts: Roundworms Are a Hidden Danger

In 2025, roundworms remain a quiet but real threat—especially to kids. The good news? Preventing infection is simple and effective with regular hygiene and pet care 🧼👨‍👩‍👧‍👦.

Wash hands, scoop poop, cover sandboxes, and deworm pets. With these basic steps, you’ll protect your family from one of the most overlooked health risks linked to our beloved pets 🐕❤️.