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
Center for Alternatives to Animal Testing effect change by working with scientists in industry, government, and academia to find new ways to replace animals with non-animal methods, reduce the numbers of animals necessary, or refine methods to make them less painful or stressful to the animals involved. CAAT also operates Altweb, a global clearinghouse for information on alternatives to animal testing, and publishes a general animal news blog, A Boundless Ethic. Center for Alternatives to Animal Testing The Johns Hopkins University Center for Alternatives to Animal Testing (CAAT) has worked with scientists since 1981 to find new methods to replace the use of laboratory animals in