Marek's Disease Virus (MDV) is the causative agent in Marek's Disease, an neoplastic viral disease seen in chickens. Occasionally misdiagnosed as an abtissue pathology, this cancer virus is a herpes virus of the α-herpes subfamily. Viruses related to MDV cause tumors and disease in turkey and other avian species. The related turkey virus is known as Herpes virus of Turkey, or HVT.

Animal diseases