Newcastle Disease in Double-crested Cormorants
Newcastle Disease was detected in Double-crested Cormorants (DCCO) in summer 2010 in both Saskatchewan and Ontario. In Ontario, 18 mortality events in DCCO were reported between 8 June and 1 September 2010; Newcastle Disease virus was confirmed in five, at Toronto (2), Mississauga(2) and Kirkfield (1) northeast of Lake Simcoe. In Saskatchewan, DCCO confirmed with Newcastle Disease were found at Jack Fish Marsh north of North Battleford, at Flotten Lake north of Meadow Lake and at Egg Lake near La Ronge. Most mortality events reported in Ontario did not appear to involve large numbers of birds. Those in Saskatchewan were not quantified. Since late July, the National Wildlife Health Center of the U.S. Geological Survey has confirmed that at least 800 double-crested cormorants have died in Minnesota, North Dakota and Wisconsin from Newcastle Disease.
Newcastle Disease is the name given to infection of birds with strains of Avian Paramyxovirus-1 (APMV-1) which are capable of causing rapidly fatal disease in domestic chickens. There are many strains of APMV-1. Only a few of these strains are agents of Newcastle Disease and the term “Newcastle Disease” should only be used for infection with virus strains highly pathogenic to chickens. Canada’s poultry populations are free of this virus and infection of poultry with the virus could have a very large economic impact on the poultry industry. Newcastle disease virus was first recognized in DCCO in Canada in 1975, and then not again until 1990 when substantial numbers of affected birds were found in Saskatchewan. Since then, it has been detected with some regularity in DCCO in the prairie provinces and on the Great Lakes. In DCCO, the virus produces severe disease in young birds up to about 12 weeks of age (fully grown and independent) but does not appear to do so in older birds. Occasionally other species are affected in outbreaks in Cormorants, but this appears to be minor relative to the number of DCCO affected. In DCCO, the virus particularly affects the brain and spinal cord. Many birds that survive infection have permanent damage to the spinal cord which results in paralysis of one or both wings and legs.
By: Ted Leighton, CCWHC – Headquarters Office