Toxocara canis/Toxocara cati – IgG antibodies and IgG avidity test

Toxocara canis/Toxocara cati IgG antibodies and avidity test is a serological test used to detect infection with Toxocara parasites — roundworms most commonly transmitted by dogs (Toxocara canis) and cats (Toxocara cati). Toxocariasis is a zoonotic disease transmitted through ingestion of parasite eggs, typically from contaminated soil or contact with animals.

The presence and avidity of IgG antibodies help distinguish between recent (acute) and past infections. This test is especially valuable when assessing unexplained symptoms such as fever, cough, abdominal pain, enlarged lymph nodes, or eosinophilia — particularly in individuals at risk of parasitic exposure.

Toxocara infection can lead to visceral larva migrans (VLM) or ocular toxocariasis, depending on where the larvae migrate in the body, making early diagnosis crucial.