As science and technology continue to advance, the use of flow cytometry is becoming more widespread. It can provide important information about cells in the body by detecting and analysing them, thereby providing a reliable basis for disease diagnosis. In the diagnosis of bovine epidemic diseases, flow cytometry can be used to detect bovine viral diarrhoea, bovine leukaemia, bovine brucellosis, bovine tuberculosis, and other diseases. This paper describes the structure of a flow cytometer (liquid flow system, optical detection system, data storage and analysis system) and its working principles for rapid quantitative analysis and sorting of single cells or biological particles. Additionally, the research progress of flow cytometry in the diagnosis of bovine epidemic diseases was reviewed in order to provide a reference for future research and application of flow cytometry in the diagnosis of bovine epidemic diseases.

Infectious bovine rhinotracheitis (IBR) is an acute, febrile, and contact infectious disease. Bovine infectious rhinotracheitis is endemic in China and even the world, which not only restricts the development of the cattle industry but also brings significant economic losses to farms. Infectious bovine rhinotracheitis virus (IBRV) contains 25 - 33 structural proteins, of which glycoproteins gB, gC, gD, gE, gG, gH, gI, gK, gL, and gM are the major structural glycoproteins of bovine rhinotracheitis virus, and all of these glycoproteins are interconnected with the assembly, invasion, release, and replication of the virus, and the only glycoproteins that are known to have been identified are gB, gC, gD, and gE. Therefore, this paper focuses on an overview of the four glycoproteins, gB, gC, gD, and gE, of bovine infectious rhinotracheitis virus (IBRV), with a view to providing a theoretical basis and reference for the differential diagnosis of IBR and the in-depth study of IBRV.

In order to determine the cause of death of 27 Small-Tailed Han sheep in a Small-Tailed Han sheep farm in Tongliao, China, we characterized Gram-positive coccobacillus isolated from dead Small-Tailed Han sheep. We have also conducted a preliminary study on the resistance mechanism and pathogenesis of the pathogen. In this study, substantial organs (heart, liver, spleen and kidney) of infected and dead sheep and blood samples of sick sheep were used as test materials. Tests such as isolation and culture of bacteria, antimicrobial susceptibility test, 16S rDNA gene identification, resistance genes detection, and pathological section observation were performed. Better growth of isolated strain on sheep blood agar medium was observed. Antimicrobial susceptibility test found florfenicol (25 mm) and amikacin (25 mm) to have the best bacteriostatic effect. The isolated strain (GenBank sequence number OP430848.1) showed 99.90% similarity to the 16S rDNA fragment of Enterococcus faecium published on GenBank. The isolate was found to harbor cfr, tetM, and ant(6)-I resistance genes. The results of pathological tissue sections showed pathological changes in the substantial organs (heart, liver, spleen and kidney) of the diseased sheep. This test provides a reference for the diagnosis, treatment, and resistance investigation of pathogenic Enterococcus faecium of sheep origin.