Toxocariasis is a rare infection caused by roundworms, Toxocara canis and Toxocara cati. It was first recognized to be associated with dogs in the 1940s. It typically affects children and can lead to profound monocular loss of vision despite known medical and surgical therapies.The eggs of Toxocara canis, T. cati, and other animal ascarid helminths mature in soil and infect dogs, cats, and other animals. Humans may accidentally ingest eggs in soil contaminated by stool from infected animals or may ingest infected transfer hosts (eg, rabbits).
Topical steroids are typically used to limit inflammation in order to prevent the development of tractional membranes and resulting retinal detachments. Other options include periocular injections and oral medication. In the case of anterior segment inflammation, cylcoplegics are also used to prevent the formation of synechiae.In the Norway, about 386 cases of Toxocara infection are reported in humans each year. Almost 10 % of the Norway population is infected with Toxocara, a parasite of dogs and cats that can be passed from animals to humans.