First Detection of Raccoon Roundworm Eggs in a Domestic Dog

Posted on 01/17/2026

First Detection of Raccoon Roundworm Eggs in a Domestic Dog

The risk to humans is extremely low

 The Los Angeles County Department of Public Health has received a report of Baylisascaris eggs, commonly known as raccoon roundworm, identified in a healthy domestic dog in the San Fernando Valley during a routine veterinary exam. This is the first formally reported detection in a dog in Los Angeles County, though infections may have occurred previously in dogs without being detected or reported.

The dog is currently being treated, and no additional infected pets or any related human illnesses have been identified. 

Public Health emphasizes that the risk to humans is extremely low. Raccoon roundworm eggs are not immediately infectious. They must remain in the environment for two to four weeks before they can cause infection. Prompt yard cleanup, good hygiene, and routine pet care greatly reduces any potential risk.  

In 2024, Public Health investigated two human cases of Baylisascaris procyonis.

What Is Raccoon Roundworm? 

Raccoon roundworm (Baylisascaris procyonis) is a parasite commonly found in the intestines of raccoons. It does not make them sick, but their feces (poop) can contain the roundworm’s eggs. While dogs can occasionally carry and shed the parasite, raccoons are the primary source in the environment. The parasite is known to be common in local raccoon populations throughout LA County.

Human infection is possible but extremely rare. Fewer than ten human cases have been reported in California since 1993. People can become infected if they accidentally eat dirt/soil, water, or other material contaminated with raccoon feces containing the eggs.

Young children, people with developmental disabilities, or people with pica (an eating disorder in which a person eats non-food items) are at highest risk because they may be more likely to put contaminated fingers, soil, objects, or even animal feces into their mouths by mistake. Baylisascaris infection cannot be spread from person to person.  

How the Public Can Reduce Risk 

The risk of raccoon roundworm illness is extremely low and can be further reduced with good hygiene, yard maintenance, and routine pet care. 

1. Practice good hygiene. Wash hands after gardening, playing outside, cleaning up after pets, or handling soil. Handwashing is especially important for young children. 
2. Pick up pet waste promptly. Pick up dog feces daily from yards, parks, and public spaces. Because eggs require two to four weeks in the environment to become infectious, quick cleanup prevents risk before it begins. 
3. Remove raccoon droppings when seen. If raccoon feces are found in yards, on patios, or on roofs, remove them as soon as possible using gloves and wash hands afterward.  
4. Avoid attracting raccoons. Do not feed wildlife. Do not leave pet food or water outdoors. Secure trash cans with tight-fitting or locking lids and remove fallen fruit. Raccoons are common in Los Angeles County, but without a food source, they typically move on. A raccoon simply passing through a yard does not pose a risk. 
5. Check roofs and elevated surfaces. Raccoons often use flat surfaces such as roofs, decks, or patios as shared bathroom areas (known as “latrines”). Trim tree branches away from buildings to prevent raccoons from climbing onto roofs. 
6. Protect children. Supervise young children during outdoor play, especially in areas where raccoons may be present. Prevent children from putting soil, dirt, or objects from the ground into their mouths. Most human cases have occurred in young children or individuals with pica (an eating disorder in which a person eats things not usually considered food). 
7. Cover sandboxes. Always cover sandboxes when not in use to prevent animals from pooping and urinating in them. 
8. Care for pets. Keep dogs on year-round parasite prevention as recommended by a veterinarian. Routine veterinary visits help detect infections early and protect pets and families. 

For more information, including prevention tips and guidance on safely cleaning raccoon latrines, visit: http://ph.lacounty.gov/vet/raccoonroundworm/ 

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