Detection and genetic characterization of feline retroviruses in domestic cats with clinical signs and hematological alterations associated with retroviral infection

Abstract Feline leukemia (FeLV) and immunodeficiency (FIV) viruses are globally distributed retroviruses that infect domestic cats and cause various syndromes, which can lead to death. The aim of our study was to detect and genotyping feline retroviruses in Mexican domestic cats. We used PCR assays to identify proviral DNA and viral RNA in 50 domestic cats with different clinical signs and hematological alterations. Endogenous FeLV (enFeLV) was identified in the genomic DNA samples from all cats in the study, and we detected enFeLV transcripts of LTR region in 48 individuals. Exogenous FeLV (exFeLV) was found in 13 cats. Furthermore, we detected FIV proviral DNA in ten cats. The enFeLV sequences were shown to be the most variable, while the exFeLV sequences were highly conserved and related to previously described subgroup A sequences. Additionally, FIV gag gene sequences revealed the presence of subtype B in the infected cats.