Synonyms and introduction

SYNONYMS AND INTRODUCTION

Synonyms

  • Bovine leukemia, Bovine leukosis, Bovine lymphosarcoma

Introduction

  • It is a lymphoproliferative disease of cattle where there is extensive proliferation of leukocyte forming tissues.
  • Bovine leukemia virus (BLV) belongs to the family Retroviridae. Only one antigenic type has been found.
  • Most infected animals develop a persistent lymphocytosis without any apparent clinical features.
  • The virus produces syncytia in cell cultures. This is used as an assay for virus or antibody detection.
  • The bovine leukemia virus (BLV) is distributed worldwide and occurs particularly frequently in dairy cattle.
  • Cattle and buffaloes are the most susceptible hosts. Although non-immune cattle of all breeds can be infected at any age with bovine leukemia virus (BLV), most infections occur in dairy cattle more than two years of age.
  • The fact that disease is seldom seen in younger animals is related to the presence of protective maternal antibody (for 5 - 6 months) and the separation of younger animals from the remaining herd until they reach sexual maturity. Most infections are inapparent and as many as 80% of a dairy herd may be infected.
  • Cattle are infected by direct contact with blood from an infected animal during blood sampling, clinical examinations, castration and dehorning.
  • Mechanical transmission by biting insects may play a role, particularly in tropical regions.
  • This disease also transmitted through vertical transmission routes such as transovarian, transplacental and through colostrum. Approximately 10 to 15% of calves born to infected cows are infected.
Last modified: Sunday, 3 June 2012, 8:10 AM