Dolly, the first cloned mammal died in the year [[1]] due to a certain lung disease.

Dolly, the first cloned mammal, died in the year 2003 due to a progressive lung disease called ovine pulmonary adenocarcinoma. 

This disease is caused by a retrovirus called Jaagsiekte sheep retrovirus (JSRV), which is common in domestic sheep. 

Dolly was cloned in 1996 by scientists at the Roslin Institute in Scotland, and she became the first mammal to be cloned from an adult somatic cell using somatic cell nuclear transfer. 

Despite being a healthy clone and giving birth to several offspring, Dolly's health deteriorated later in life, and she developed this fatal lung disease. 

Her death raised questions about the health risks associated with cloning and the potential impact of cloning on the welfare of animals. 

Nonetheless, Dolly's birth remains a significant achievement in the field of genetics and reproductive biology, paving the way for further research and innovation.