You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Dog

Context:
Toxocara canis (dog roundworm) eggs in dog feces can cause toxocariasis. In the United States, about 10,000 cases of Toxocara infection are reported in humans each year, and almost 14% of the U.S. population is infected. In Great Britain, 24% of soil samples taken from public parks contained T. canis eggs. Untreated toxocariasis can cause retinal damage and decreased vision. Dog feces can also contain hookworms that cause cutaneous larva migrans in humans.

Question:
If toxocariasis is left untreated, what can happen to a person?

retinal damage and decreased vision