| WI - Cormorant Research Group | News | created on 23-10-2001 |
In 1992, mortality, estimated in the thousands, due to Newcastle Disease (ND), which is caused by Avian Paramyxovirus-1 (PMV-1), occurred in colonies of double-crested cormorants on the Great Lakes. This was part of a panzootic that affected cormorant and pelican colonies from northern Alberta through the prairies and Great Lakes to the St. Lawrence River. No epizootics have occurred in Ontario since, but PMV-1 was isolated from cormorants and a caspian tern (Hydroprogie caspia) with neurological signs in August, 1995 [CCWHC Newsletter, Vol. 3 (3)]. In late August, 1996, cormorants unable to fly and with leg paralysis, were brought to wildlife rehabilitation clinics in Bowmanville and Sarnia and subsequently submitted to the CCWHC laboratory in Guelph. Necropsies were conducted and tissues were sent to the avian virology laboratory of the OMAFRA for virus isolation. The bird brought to the Avicare centre in Bowmanville was from the Presqu'ile colony at the eastern end of Lake Ontario, a colony in which affected birds were detected in 1995. PMV-1 was isolated from brain and kidney of this bird. Agriculture and Agri-Food Canada has treated this isolate as positive for ND, placing this facility under quarantine. The colony of origin for the bird sent from Sarnia is not known but PMV-1 has been isolated from it as well, and identified as ND. Both birds were found late in the summer, after juvenile birds had dispersed from the colonies. Large-scale mortality has not been detected on any of the colonies monitored by the Canadian Wildlife Service, and these birds presumably represent survivors of the disease that have been left with neurological impairment. Surveillance for ND has been achieved by a co-operative effort of biologists, rehabilitators, OMAFRA, CCWHC and Agriculture and Agri-Food Canada. (Doug Campbell - CCWHC Ontario Region; Doug Key, Avian Virology Laboratory, VLS).