Jaagsiekte sheep retrovirus Jaagsiekte sheep retrovirus Jaagsiekte sheep retrovirus (JSRV) is a betaretrovirus which is the causative agent of a contagious lung cancer in sheep, called ovine pulmonary adenocarcinoma. JSRV is the virus that is the cause of the contagious lung tumors in sheep called ovine pulmonary adenocarcinoma (OPA). The disease has also been called "jaagsiekte", after the Afrikaans words for "chase" ("jaag") and "sickness" ("siekte"), to describe the respiratory distress observed in an animal out of breath from being chased, indicating the breathing difficulty experienced by infected sheep. Transmission of virus is through aerosol spread between sheep. The exogenous infectious form of
Fisher (animal) the Adirondack Mountains of New York. He recounts three sightings, including one where he witnessed a fisher attacking a porcupine. In "Winter of the Fisher", Cameron Langford relates a fictional encounter between a fisher and an aging recluse living in the forest. The recluse frees the fisher from a trap and nurses it back to health. The fisher tolerates the attention, but being a wild animal, returns to the forest when well enough. Langford uses the ecology and known habits of the fisher to weave a tale of survival and tolerance in the northern woods of Canada. Fishers are mentioned