目的 对广州和东莞市宠物犬感染犬瘟热病毒（CDV）的情况进行病原鉴定和分析，为监测CDV的遗传变异情况和防治犬瘟热（CD）提供数据基础。方法 从表现CD症状的犬只中鉴定了17份CDV阳性样本，采用RT-PCR的方法克隆得到这些野毒株的血凝素（H）基因序列，采用生物信息学方法进行序列比对分析。结果 17株CDV的H基因核苷酸与氨基酸序列的相似性分别为97.4%~100.0%和97.5%~100.0%，与Onderstepoort、Lederle和Convac等疫苗株相比，其核苷酸与氨基酸序列相似性分别为90.3%~91.5%和89.4%~90.8%。进化树分析结果显示，17株CDV野毒株均属于Asia Ⅰ型，与疫苗株的分支较远；本研究鉴定的野毒株已进化形成9个潜在的N-糖基化位点。结论 Asia Ⅰ型CDV仍为该地区的流行基因型，基因型较稳定，但与疫苗株相比形成了一定的进化距离和出现了大量的变异。因此，继续监控CDV在犬群中的进化，掌握其遗传变异状况具有重要意义。
Objective To perform etiological investigation of canine distemper virus (CDV) infection in dogs from Guangzhou and Dongguan, moniter the genetic evolution of canine CDV, and provide a data basis for the prevention and control of canine distemper (CD).Method Seventeen CDV positive samples were identified from dogs with CD symptoms. The haemagglutinin (H) genes of these wild strains were obtained by RT-PCR, and the H gene sequences were compared and analyzed through bioinformatics approach.Result The similarities of nucleotide and amino acid sequences of H genes from 17 CDV strains were 97.4% to 100.0% and 97.5% to 100.0%, respectively. Compared with vaccine strains such as Onderstepoort, Lederle and Convac, the similarities of nucleotide and amino acid sequences of H genes from these CDV strains were 90.3% to 91.5% and 89.4% to 90.8%, respectively. Phylogenetic tree analysis showed that 17 CDV wild strains belonged to Asia I subtype and were distant from the vaccine strains. The identified wild strains had evolved to containing nine potential N-glycosylation sites.Conclusion Asia I CDV is still an epidemic subtype in this region and this subtype is stable, but it has formed a certain evolutionary distance and a large number of mutations compared with vaccine strains. Therefore, it is of great significance to continue to monitor the evolution of CDV in dog populations.