Marek's disease(redirected from Marek disease)
a transmissible disease of chickens caused by an alphaherpesvirus that carries some retrovirus oncogenes; characterized by a tumorous, mononuclear infiltration of peripheral nerves, causing limb paralysis. Infiltration of other organs and tissues is common, especially of the iris, causing blindness, and of the ovaries. Vaccination is highly effective and without it serious outbreaks with heavy losses can occur. Called also neural lymphomatosis, neurolymphomatosis gallinarum.