Epidemiological Characteristics Of Dogs And Cats In Shenyang And Genetic Evolution Of Canine Parvovirus

In recent years,with the rapid development of national economy and urbanization,the number of pet dogs and cats has been increasing,and the quality of life and health of pets have attracted more attention.In this study,the incidence of four types of pet common infectious diseases and parasitic diseases in shenyang area was investigated,and statistical analysis showed that the monthly average incidence of mycosis,bacterial disease,parasitic disease and viral disease was significantly correlated with the monthly average temperature(P<0.001),with a time lag effect of two months.In addition,the monthly average data from 2013 to 2017 were analyzed in time series,and the ARIMA model was established to predict the incidence in the next five years.The epidemiological statistical analysis in this study showed that canine parvovirus disease was the most frequently diagnosed infectious disease in pet hospitals in Shenyang.Canine parvovirus(canine parvovirus)is one of the major infectious diseases that harm carnivores.CPV,FPV and MEV are also closely related to canine parvovirus.PCR screening was performed on 9 samples of CPV virus collected between 2018 and 2019,and VP2 gene and NS1 gene of the virus were cloned and sequenced,amino acid site mutations were analyzed,homology comparison and phylogenetic tree construction were performed,which provided theoretical basis for the prevention and control of canine parvovirus disease and provided basis for the development of CPV vaccine of different subtypes.The results showed that all the five sequences were of CPV-2c type.The sequence of the strain isolated from Beijing and Jilin area was close to the genetic relationship,while that from Italy and Japan was far away.10 nucleotide mutations(nt14,16,520,817,819,1016,1042,1109,1278,and 1490)in the VP2 sequence resulted in nine amino acid mutations(aa5,6,174,273,339,348,370,426,497).The 6 NS1 sequences were compared with 7 standard strains.Found that there are 27 nucleotides(nt67,178,196,206,210,336,433,555,616,726,905,969,1017,1059,1207,1267,1463,1488,1558,1625,1664,1715,1728,1736,1792,1891,1953)in 12 amino acid mutations(aa23,60,66,69,145,206,302,403,423,460,520,555).Compared with other regions,there was no significant difference in the evolution rate of canine parvovirus in shenyang area,and a total of 12 sites were found to have positive selection.These mutations may be the cause of virus mutation,and the newly discovered mutation sites also provide a reference for future studies.