Toxocara is a parasitic helminth worm, which continues to stimulate both public concern and scientific interest. toxocara canis and T. Cati are gastrointestinal parasites of dogs and cats and their eggs can contaminate the environment, thus exposing humans and other mammals and birds to infection. Many questions remain about the host-parasite relationship, it's epidemiology and public health significance. Veterinarians and clinicians are interested in its importance as a zoonosis and the parasite's capacity to enter the human eyes is of concern to opthamologists. This book provides a comprehensive review of toxocara and the disease it causes known as toxocariasis.