| The canine parvovirus is a deadly infection disease which characterized by acutevomiting, diarrhea and leukopenia. Natural cases of canine parvirus infection oftenoccurs.Though the CPV vaccine was used in disease, the incidence of puppy mortalityis highly. In recent years, with a substantial increase in raising the amount ofexperiments dogs and pet dogs, the Canine parvovirus are becoming serious, it bringsignificantly losses to the breeding industry. CPV is a single-stranded negative linearDNA virus, has a strong resistance to physical and chemical factors. The dog is themainly source of infection, especially in contact with the feces of dogs, because thevirus could survive in feces for a long time, and the pathogenicity isn’t reduce. Thevirus has a high level in feces, and the infectious is also the strongest.We collect the clinical samples from infectious diarrhea dogs in Chang-chun, weidentified the samples by PCR, and separated the virus by F81cell. The result showswe separated four CPV strains from five CPV positive samples through microscopy,hemagglutination and cell infected with spectrum test. At last, we named the fourstrains as CPV-BM, CPV-LTS, CPV-GYW, CPV-GZL.To determine the gene-type of the CPV trend in Changchun, prevent and treat theanimals better, we amplicated and determined the sequence of CPV VP2gene. Thesequence analysis showed that the426amino acids of the four strains is Asn, theybelong to CPV-2a. The mainly type of CPV is CPV-2a in Changchun. CPV-DM is anearly strains, compared to CPV-BM, CPV-LTS, CPV-GYW, CPV-GZL is lowhomology, and amino acid differences are larger. In recent years, CPV strains are stillevolving.My study started from the infection of virus and different patterns of infection,isolated the virus from the diagnosis of dogs, identified and analysised it. We infectedin experimental animals and established a model of canine parvirus infection. Thestudy provide the necessary animal models for the development of antivirus drugs,and prepare for the evaluation of new antiviral drug dfficacy. To provide the animal model for CPV vaccine development and treatment of drug evaluation, Theexperimental dogs are ordinary pet dogs which is2-3months old and the CPV test isnegative, select BM strains as the attack-virus, Performing clinical, hematological,serological, virus isolation and pathological by four methods including oralapplication, respiration and eye-drop application, intramuscular injection andhypodermic injection, the dose is1ml/kg, we collected fecal to detect the discharge ofthe virus, tested the blood changes on2,4,6,8,10,12days.The results shows the oral group is the first to occur the clinical symptoms whichshows depression, anorexia, weight loss, dehydration and so on. The averagetemperature increased from the next day to the second day, the average weightdeclined on the fifth day, three dogs appeared hemorrhagic in the fecal,100%of thewhole group is sick, and the mortality rate is75%. The course of the disease is6-8d.The lowest WBC was2.32×109/L; The eyedrop application group also shows theclinical symptoms after infection virus, but the time is late than the oral group, Theaverage temperature increased from the fourth day to the sixth day, the average weightdeclined on the sixth day, one dog appeared hemorrhagic in the fecal, the disease rateis75%, the the mortality rate is25%. The lowest WBC was4.8×109/L. Theintramuscular injectionand hypodermic injection group didn’t show clinical symptoms.The result shows that oral infection is the best pathway in the establishment of theinfection, with typical clinical symptoms, and the incidence is100%. Our studyprovide a stable animal model for the evaluation of CPV vaccines and treatmentdrugs. |
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