What Are Roundworms?
Roundworms (Toxocara canis) are the most common intestinal parasite in dogs worldwide. Nearly all puppies are born with roundworms or acquire them through their mother's milk within the first weeks of life.
~36%
Prevalence
of shelter dogs test positive
3-7 inches
Adult worm size
White/tan, spaghetti-like
~200,000
Eggs per day
Per adult female worm
Up to 5 years
Egg survival in soil
Extremely hardy
Symptoms in Dogs
- Pot-bellied appearance (especially in puppies).
- Visible worms in stool or vomit — white, spaghetti-like.
- Dull coat and poor body condition.
- Diarrhea or vomiting.
- Slow growth in puppies.
- Coughing (larval migration through the lungs).
- Many dogs show no symptoms at all.
Human Health Risks
Roundworms are zoonotic — humans can become infected by accidentally ingesting eggs from contaminated soil or surfaces. Children are at highest risk due to hand-to-mouth behavior during outdoor play.
- Visceral larval migrans — larvae migrate through internal organs.
- Ocular larval migrans — larvae reach the eye, potentially causing vision loss.
- An estimated 10,000 human roundworm infections occur annually in the United States.
Warning
Children under 5 are at greatest risk. If you have young children and dogs, monthly deworming and immediate yard waste removal are non-negotiable safety measures.
Treatment and Prevention
- Puppies should be dewormed at 2, 4, 6, and 8 weeks of age, then monthly until 6 months.
- Adult dogs should be on monthly heartworm prevention that includes roundworm coverage.
- Fecal tests should be performed 1-2 times per year.
- Remove dog waste from the yard daily — eggs become infective after 2-4 weeks in the soil.
- Wash hands after handling dogs or playing in areas where dogs defecate.
Yard Contamination Timeline
Understanding the roundworm egg maturation timeline explains why prompt waste removal matters:
| Timeframe | What Happens |
|---|---|
| Day 1 | Fresh eggs shed in feces — not yet infective |
| Days 2-14 | Eggs begin developing in soil — still not infective |
| Days 14-28 | Eggs become infective (embryonated) under warm, moist conditions |
| Months to years | Infective eggs persist in soil — resistant to most disinfectants |
Tip
Removing waste within 7 days prevents roundworm eggs from becoming infective. Weekly professional cleanup keeps your yard within the safe window.
Related Resources
- Get a Free Quote →
Professional pet waste removal keeps your yard safe and makes health monitoring easier
- Healthy Poop Color Chart →
Visual reference for normal vs abnormal dog poop colors