Ovine pulmonary adenocarcinoma be predisposed to OPA. Most affected sheep show signs at 2 to 4 years of age. OPA is not a notifiable disease, and therefore it is difficult to assess its prevalence. OPA was first described in the UK in 1888, and described in detail in South Africa in 1891. The disease was initially known as "jaagsiekte" , a word derived from Afrikaans, meaning "chasing sickness," so called because animals are in respiratory distress as if they are out of breath from being chased. It has also been known as sheep pulmonary adenomatosis and ovine pulmonary carcinoma. OPA has been used
Animal slaughter animal unconscious, and thus not susceptible to pain, but not necessarily dead. In the second stage, the animal is killed, usually by slitting its throat and allowing the blood to drain. Countries differ in the methods which have been legalised for different species or different ages, some regulations being governmental, others being religious. Various methods are used to render an animal unconscious during animal slaughter. The measures for sanitary checks, animal welfare protection and slaughtering procedures are harmonised throughout the European Union, and detailed by the European Commissions' regulations CE 853/2004, 854/2004 and 1099/2009. In Canada, the handling and slaughter