Serological And Pathogenic Study Of The Major Infectious Diseases In Guizhou Pony

Guizhou pony is one of the few natural pony breed on the world, it is a precious genetic resources formed under the dual influence of natural environment and artificial selection. Guizhou pony mainly in the remote mountainous area of southwest Guizhou. And the most famous Guizhou pony distribute in sparks township, Ziyun County, Anshun City. There was a phenomenon of mass mortality in Guizhou pony herd, especially in Dongsang village, which incidence rate was 12%, the mortality rate was 12%. And the cause of death was unknown. According to the analysis of clinical symptoms of horses, we suspected that it may was infectious diseases caused by Theileria equi, Babesia caballi, Equine Infectious Anemia virus, Equine arteritis virus and Equine herpesvirus type-1. In this study, blood smear microscopy, enzymelinked immunosorbent assay and polymerase chain reaction methods was applied to find the real cause of its large number of death in Guizhou pony.PCR and c ELISA methods was used to study the serological and molecular etiology of T.equi and B.caballi. The results showed that the T.equi antibody positive rates of Guizhou pony, Southwest horse and Ili horse respectively were 23.86%, 11.43%, 31.71% by c ELISA. But only the Ili horse samples was detected the antibody of B.caballi, and that positive rate was 85.37%. All horses were detected the 18 s r RNA gene of T.equi and B.caballi. And the detection rate of the 18 s r RNA gene of T.equi was 78.41%, 62.86%, 68.29%, respectively in Guizhou pony, Southwest horse and Ili horse.,while the 18 s r RNA gene of B.caballi was 11.36%, 11.43%, 90.24%. respectively. Giemsa-stained blood smear was prepared to observe the T.equi and B.caballi in red blood cell. Intact protozoans of T.equi and B.caballi were observed in red blood cells of horses at Giemsa-stained slide smears, which size and morphological characteristics consistent with the literature described.There were some differences between the results of PCR and c ELISA methods, the positive rate of PCR results are generally higher than the c ELISA, which may be due to the PCR method has higher detection sensitivity. In addition, it may be that some of the horses sample were collected in the early stages of infection, which no production of antibodies. Some samples was detected by c ELISA revealed positive but PCR is negative. Which may due to the antibodies can be demonstrated yet when the piroplasms have been eliminated. But some samples found positive only with PCR, the reason for this is that antibodies may have not yet developed indicating a fresh infection.The samples of Guizhou pony, Southwest horse and Ili horse were examined for the presence of antibodies against EIAV?EAV and EHV-1. All samples were not detected the antibody of EIAV. The positive rate of EAV in Guizhou pony, Southwest horse and Ili horse was 48.08%, 22.86%, 10.81%, and the EHV-1was 99.38%, 97.14%, 100%. Another,the EHV-1 DNA was amplified by PCR, in Guizhou pony, southwest horse and Yili horse, the EHV-1 DNA detection rates were 94.23%, 80%, 83.78%, respectively. The clinical symptoms are similar between EIAV and equine piroplasmosis, and all samples revealed EIAV antibody negative. This provided a theoretical basis for the diagnosis of equine piroplasmosis. The positive rate of EHV-1 is very high, but the disease mortality is not high, it may be only a secondary infection. But the positive rate of EAV was higher, and the EAV has a higher mortality, indicating that EAV may be one reason of death Guizhou pony.All results showed that T.equi and EAV may be the main reason to cause a large number death in Guizhou pony. According to the clinical symptoms of horses, we took ivermectin, blood worms Di and attach a red combo drug treatment in a timely manner. At the same time applied the antibiotics to secondary infection treatment, until the horse recoveried. Eventually, the death rate of the local horses reduces effectively.In summary, this research was to study the serological and molecular etiology of major communicable diseases with serological test and PCR method in Guizhou pony. It was not only reduced the economic losses of local farmers, and avoided the extinct of Guizhou pony. In addition, it provides a reliable theoretical basis for the diagnosis, treatment and prevention of this disease.