Roundworms are commonly transmitted via which routes?

• A. In utero, breastmilk, and feces
• B. Ingesting fleas
• C. Direct contact with infected animals
• D. Through coughing

Answer: (A)

Roundworms in dogs are spread mainly through three routes: the larvae can be passed from a pregnant mother to her developing puppies across the placenta, after birth through the mother's milk, and by dogs ingesting eggs shed in feces that have contaminated the environment. The eggs are shed in feces and become infective after spending time in the soil, so a dog can pick them up by oral ingestion. This combination of transplacental, transmammary, and fecal-oral transmission is why the option listing in utero, breastmilk, and feces is the best fit.

Other routes like acquiring parasites by fleas or through direct contact or coughing are not how roundworms typically spread. Fleas are commonly associated with tapeworm transmission, not roundworms, and coughing doesn’t transmit roundworm eggs or larvae.