Toxocariasis is a parasitic condition caused by the larvae of two species of Toxocara roundworms: Toxocara canis (from dogs) and Toxocara cati (from cats). Many people who are infected with Toxocara never develop any signs or symptoms of the condition. In those who do become sick, symptoms may present as: Ocular Toxocariasis - when the larvae infect the eye and cause vision loss, eye inflammation, and/or damage to the retina. Visceral Toxocariasis - when the larvae infect various organs of the body (i.e. the liver or the central nervous system) and cause fever, fatigue, coughing, wheezing, and/or abdominal pain. Toxocariasis is generally spread through dirt that has been contaminated with animal feces that contain infectious Toxocara eggs. Young children and owners of dogs and cats have a higher chance of becoming infected.