10 Diseases You Can Actually Get from Your Dog

8. Giardiasis: Waterborne Parasite Danger

Giardiasis is a diarrheal disease caused by a tiny parasite called Giardia. It affects both dogs and humans, spreading easily through contaminated water, soil, and surfaces. While rarely life-threatening, it can cause prolonged digestive problems.

How Humans Get Giardiasis

The Giardia parasite lives in the intestines of infected animals and is passed in their feces. People can become infected by:

• Handling infected dog poop and forgetting to wash hands.

• Drinking untreated water from lakes, rivers, or puddles where Giardia survives.

• Playing outdoors where soil or grass is contaminated with feces.

The parasite forms tough “cysts” that can live outside the body for weeks, making it easy to spread.

Symptoms in Humans

Symptoms usually begin 1–3 weeks after exposure and may include:

• Watery, greasy diarrhea that floats and smells foul

• Abdominal cramps, bloating, and gas

• Nausea, fatigue, and weight loss

• Symptoms may last 2–6 weeks and can return if untreated

In some cases, people may carry Giardia without symptoms but still spread it.

Prevention Tips

You can lower your risk of infection with simple steps:

• Don’t let dogs drink from lakes, rivers, or puddles.
• Wash your hands thoroughly after cleaning up pet waste.
• Disinfect bowls and surfaces regularly with boiling water or bleach solutions.
• Avoid close contact with unknown dogs during outdoor walks or activities.

Quick Fact: The CDC notes that Giardia is one of the most common waterborne parasites in the U.S., infecting over 2 million people every year.