DNA barcoding shows that Toxocara cati infecting domestic and wild felids is a species complex.

The insufficient attention paid to the importance of Toxocara cati in the epidemiology of toxocariasis has resulted in significant gaps in the understanding of the true zoonotic potential of this parasite. Therefore, further research is necessary to understand its biology and epidemiology. In this article, the hypothesis of possible speciation in the T. cati complex was tested using cox1 sequences from T. cati individuals infecting domestic and wild felids from different parts of the world. Using DNA barcoding, a phylogenetic analysis was performed that grouped T. cati representatives into five clades according to the host species. The differences in cox1 sequences between T. cati from domestic cats and T. cati from wild felids were substantial (6.68 %-10.84 %). The results of the Assemble Species by Automatic Partitioning analysis supported the species status of the clades. However, the determination of the actual species diversity of the T. cati complex would necessitate an analysis of a wider range of wild hosts. A detailed understanding of the genetic diversity and phylogenetic relationships between species in the T. cati complex will contribute to more accurate identification, diagnosis and better control of these parasites.