Lateral Flow Strip-Compatible Nucleic Acid Testing for Facile Diagnosis of Infectious Pet Diseases

Rapid detection of pet-related pathogens enables doctors/owners to identify potential illnesses early, thus facilitating timely treatment, lowering veterinary expenses, and decreasing the risk of zoonotic diseases. Currently, lateral flow immunoassay (LFIA) strips are mostly adopted for pet disease diagnosis but suffer from poor sensitivity that may cause delays in illness diagnosis. Here, we propose the combination of recombinase polymerase amplification (RPA, applicable at body temperature) with lateral flow assay (LFA, readout of amplicons) strips for the rapid and sensitive diagnosis of infectious pet diseases. To improve the detection specificity, T7 exonuclease (T7 Exo)-assisted selective recognition of the RPA amplicons was adopted, which endowed compatibility of RPA with LFA detection. For feline panleukopenia virus (FPV) detection, the proposed RPA-LFA exhibited a sensitivity enhancement of 10⁴-fold when compared with the conventional LFIA_FPV. The results of FPV analysis in real cat feces anal swab samples (collected from a local pet hospital) were in good agreement with those obtained by PCR. The universality of the proposed RPA-LFA was further demonstrated for the detection of canine parvovirus (CPV) commonly found in dogs. Besides, using LFA with dual test lines, the simultaneous detection of FPV and CPV was also achieved. The overall results highlighted the appealing feature of RPA-LFA in the facile diagnosis of infectious pet diseases.