Whipworms have eggs that persist in the environment and are not always cleared by deworming. Which statement is true?

• A. Whipworms are easily eliminated by standard dewormers
• B. Whipworms are not infectious to dogs
• C. Whipworm eggs persist for years
• D. Whipworms infect cats but not dogs

Answer: (C)

Whipworm eggs are extremely hardy in the environment, which is why they can keep causing infections long after treatment. In dogs, whipworms live in the large intestine and lay eggs that are shed in feces. Those eggs need time to develop in soil to become infective, and their shells resist drying, heat, and many cleaning methods. This environmental reservoir means a dog can appear cured after a deworming treatment but still become reinfected from contaminated soil later. So the statement that whipworm eggs persist for years best reflects the biology and reality of controlling these parasites. Because of this persistence, treatment often needs to be repeated and environmental sanitation steps are important to reduce reinfection. The other ideas—being easily eliminated by standard dewormers, not being infectious to dogs, or infecting cats but not dogs—don’t fit the actual life cycle and epidemiology.