Roundworms can be transmitted via which routes?

• A. In utero, breastmilk, and feces
• B. Ingesting fleas
• C. Direct contact with soil
• D. Inhalation

Answer: (A)

Roundworms are transmitted through three main pathways. First, transplacental transmission allows the parasite to pass from an infected mother to her fetus during pregnancy, so puppies can be born already infected. Second, transmission through milk means larvae can be passed to nursing puppies, continuing infection after birth. Third, eggs shed in feces contaminate the environment and are ingested by the dog, often via contaminated soil, water, or objects; this fecal-oral route is a common way for infection to spread in young dogs and in households with infected animals. Ingesting fleas is a route for other parasites like tapeworms, not roundworms, and inhalation is not a transmission route for roundworms. So the combination of in utero, breastmilk, and fecal-egg ingestion best describes how roundworms are transmitted.