10 Diseases You Can Actually Get from Your Dog

6. Toxocariasis: Worms That Can Affect Your Eyes and Organs

Toxocariasis is a parasitic infection caused by roundworms (Toxocara canis) that live in a dog’s intestines. Dogs—especially puppies—can shed thousands of microscopic eggs in their poop, which contaminate soil, sand, and even household surfaces.

How Humans Get Toxocariasis

Humans don’t catch the adult worms, but they can ingest the microscopic eggs without realizing it. Infection happens when:

• Accidentally swallowing eggs from contaminated soil, sand, or surfaces.

• Handling dog feces and not washing hands properly.

• Children playing in parks or yards where dog waste hasn’t been picked up.

Once inside the body, the eggs hatch into larvae and can travel through the liver, lungs, or even the eyes.

Symptoms in Humans

Many people don’t show obvious symptoms, but when they do appear, they may include:

• Fever, fatigue, and stomach pain

• Coughing or breathing problems when larvae reach the lungs

• Eye pain, blurred vision, or vision loss (in rare but serious cases known as ocular toxocariasis)

• Organ damage if larvae migrate to the liver or other tissues

Prevention Tips

The best defense is good hygiene and regular dog care:

• Deworm your dog regularly, especially puppies.
• Pick up dog poop immediately in yards, parks, and playgrounds.
• Wash hands after handling dogs or soil.
• Teach kids not to play in soiled areas, sandboxes, or grass where pet waste is common.

Quick Fact: The CDC estimates that millions of people in the U.S. have been exposed to Toxocara, but only a small number develop severe illness. Children are the highest risk group.