Detection of larvae of Toxocara cati and T. tanuki from the muscles of free-ranging layer farm chickens.

Although raw or undercooked livestock meat or viscera has been suggested to be a source of human toxocariasis, there have been few reports on the prevalence of Toxocara larvae in the tissue of livestock animals. To investigate the presence of Toxocara larvae in chickens, we examined 50 culled chickens from a commercial layer farm. The liver, breast meat, and thigh meat were separated individually and artificially digested to examine for the presence of larvae. Nematode larvae were detected in 2 out of 50 chickens. One larva was detected from the breast meat, and it was molecularly identified as Toxocara tanuki. The other from the thigh meat of another chicken was molecularly identified as Toxocara cati. The present study demonstrated for the first time that T. tanuki larvae do infect chickens in the natural environment. The fact that Toxocara spp. larvae were found in muscles of farm chickens suggests that consumption of raw or undercooked chicken meat may present a risk for human toxocariasis.