Very much so. Toxocara roundworms of dogs and cats have significant public health implications. Humans are infected by the accidental ingestion of infective embryonated Toxocara eggs present in contaminated soil (geophagia), dog hair, unwashed hands or raw vegetables.
Untreated puppies are a major source of environmental contamination, as they can excrete millions of Toxocara eggs in a day. Infection can also occur through the consumption of undercooked game and offal but this thought to be uncommon.
The larvae hatch from the ingested eggs, penetrate the small intestine and migrate to different tissues in the body, inducing inflammatory responses.
Migration of Toxocara larvae leads to a number of syndromes, including visceral larva migrans (VLM), ocular larval migrans (OLM), neurological toxocariasis (NT) and covert toxocariasis (CT). The severity of symptoms depends on the number of infective eggs ingested.
Risk of disease in humans is particularly high in: (i) children with pica tendency (i.e. soil-eating), because they are more likely to ingest embryonated eggs from soil and contaminated items than those not exhibiting this behaviour; (ii) children between 2 and 4 years of age; and (iii) individuals growing up in a poor socio-economic area. T. leonina is increasingly thought to have some zoonotic potential but is of less importance than the risk from T. canis and T. cati.
