Helminths of British dogs: Toxocara canis—a veterinary perspective

An important factor in the life‐cycle of Toxocara canis is the dissemination of ova into the host's environment. This provides a reservoir for infection of the bitch with subsequent transmission of larvae to the fetus. Additionally, other warm‐blooded animals may acquire infection, thereby acting as paratenic hosts in subsidiary predator‐prey cycles. Embryonated ova are infective for man and may on occasion result in clinical disease. Information assessing the extent of such environmental contamination in the UK and denning the sources of the T. canis ova is reviewed. These data are of immediate practical importance as each contribution to the understanding of the epidemiology of toxocariasis facilitates the formulation of effective control measures.