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
Set animal the head of a donkey, it is possible the donkey was the inspiration for the Set animal. Others have speculated that it is a purely fantastic or composite animal, which never existed in nature; this was the opinion of Egyptologist E. A. Wallis Budge. Because the name "sha" is not as familiar as that of Set, and has no independent mythology associated with it, the animal is commonly referred to as "Set" or "Set animal" or the "Typhonian animal", so-called because the Greeks equated Set or Sutekh with the monster Typhon. Set animal In ancient Egyptian art, the Set animal,