Introduction. Differentiation of vaccine strains and field isolates of bovine type 1 herpesvirus Varicellovirus bovinealpha1 is an urgent task to improve the quality of diagnosis of infectious bovine rhinotracheitis (IBR). There are several approaches to solve this problem. The most successful methods are those proposed by R.W. Fulton and S.K. Chothe in 2013 and 2018, respectively. The aim of the study is to test the methods proposed by R.W. Fulton and S.K. Chothe to study the possibility of their optimization and implementation in routine laboratory diagnostics of IBR in Russia. Materials and methods. 4 vaccine strains and 6 field isolates of the IBR virus were studied using PCR-based algorithms by R.W. Fulton and S.K. Chothe to determine the presence of single nucleotide substitutions at 11 control points of the virus genome in comparison with the nucleotide sequence of the reference strain Cooper JX898220. Results. Both methods confirmed that the domestic strains of the IBR virus used for the production of inactivated vaccines originate from field isolates of the virus. Both the reference and modern epizootic isolates obtained by us and our colleagues at different times in Russia are epizootic strains that have no direct connection with the large-scale use of foreign vaccines, including live ones, both among our own indigenous livestock and among animals imported from abroad. None of the methods we tested allows us to distinguish between Varicellovirus bovinealpha1 and Varicellovirus bovinealpha5. Conclusion. The methods proposed by R.W. Fulton (2013) and S.K. Chothe (2018) can be used to differentiate vaccine strains and field isolates of IBR virus only after our recommended preliminary differentiation of BoHV of types 1 and 5.

The distribution and genetic diversity of economically significant pathogens, including porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), porcine circovirus type 3 (PCV3), and porcine parvovirus 1 (PPV1), across extensive Russian territory within wild boars that serve as reservoirs remain poorly characterized. This study aimed to conduct a molecular epidemiological survey of these viruses in wild boar populations. The samples of 476 wild boars, collected across Russia between 2021 and 2025, were tested by PCR for the detection of viral genomes. While PRRSV was not detected, we found high detection rates for PCV2 (34.9%), PCV3 (35.5%), and PPV1 (25.4%). For PCV2, the co-circulation of two genotypes, PCV2b (5/53) and PCV2d (48/53), was observed. All 29 PCV3 sequences belonged to the PCV3a genotype. For PPV1, the presence of the PPV1a, PPV1b, and PPV1d genotype, as well as unclassified isolates, was shown. Co-infection of different viruses was detected: PCV2/PCV3 (16.0%), PCV2/PPV1 (6.9%), PCV2/PCV3/PPV1 (6.9%), and PCV3/PPV1 (4.4%). This is the first comprehensive study that demonstrates the wide dissemination and genetic diversity of PCV2, PCV3, and PPV1 within the wild boar population in Russia and highlights their role as a potential reservoir in viral evolution and spread.