Evaluation of a 70 kDa Excreted/Secreted Coproantigen Immunoassay for the Detection of Toxocara canis in Dogs

Background: We aimed to develop a sandwich ELISA, using polyclonal antibodies against excretory/secretory (E/S) antigens specific to coproantigens present in Toxocara canis-positive dogs. Methods: Antibodies were produced at Biological Sciences School, Autonomous University of Nuevo León, México in 2023 by immunization of rabbits with antigenic extracts from in vitro cultures of T. canis larvae. Assays were performed on 100 stool samples from pet dogs, measuring sensitivity, specificity, and cross-reactivity against other parasitic infections. Results: High values of sensitivity (100%), specificity (90.9%), and positive (93.47%) and negative (95.45%) predictive values were obtained, respectively. We obtained an E/S protein with a molecular weight of 70 kDa, which showed high sensitivity and specificity by ELISA, but it presented cross-reactivity against Ancylostoma caninum and Strongyloides stercoralis. Conclusion: Additional studies are necessary to increase the specificity percentage since this assay demonstrated significant potential as a useful and inexpensive diagnostic tool for immunodiagnostic in dog feces.