Which two species are associated with toxocariasis as Toxocara roundworms?

• A. Toxocara canis and Toxocara cati
• B. Toxocara canis and Toxocara leonina
• C. Toxocara cati and Toxocara mystica
• D. Toxocara mystica and Toxocara canis

Answer: (A)

Toxocariasis is linked to the two Toxocara species that infect dogs and cats. Toxocara canis is the canine roundworm and Toxocara cati is the feline roundworm; humans are accidental hosts who ingest infective eggs from contaminated soil, hands, or objects. Once inside, the larvae migrate through tissues, causing manifestations such as visceral larva migrans or ocular larva migrans. Other listed names don’t represent the common human-related toxocariasis culprits—one is not a recognized human pathogen in this context, and the other is not associated with human toxocariasis as a significant agent. So the pair most associated with toxocariasis is canis and cati.