Observations on avian pasteurellosis in Britain.

An investigation into the extent and significance of Pasteurella multocida infections of birds and poultry in Britain during a three year period (1974--1977) was undertaken. This was achieved by means of postal questionnaires, coupled with the biochemical and serological examination of bacterial isolates from 91 outbreaks in poultry and from nine cases in other avian species.     

Observations on pigeon circovirus infection in Ontario.

Subclinical pigeon circovirus infection was diagnosed in 1-day-old to 6-week-old birds from a loft with no history of clinical disease. Pigeons from other lofts presented with various illnesses and were found at necropsy to be concurrently infected with pigeon circovirus.     

Observations on the pathology of canine microsporidiosis.

The available literature on canine microsporidiosis indicates that this disease, primarily of young dogs, is a distinct clinicopathological entity. It has been confused with canine distemper and rabies, and must be differentiated from toxoplasmosis. Information available on the spectrum of pathological change associated with this disease is incomplete but a distinct pattern emerges from a study of the reports. The aetiological agent appears to have a predilection for the central nervous system and kidneys, but other tissues and organs, and especially the liver, may also be infected. Vasculitis and perivasculitis, which may include fibrinoid necrosis, seem to be a basic lesion. Cellular inflammation ranges from polymorphonuclear leukocyte infiltration in areas of necrosis to focal granulomas. There may be no cellular reaction to compact groups of organisms. Histopathological and ultrastructural studies of this case augment our knowledge of the pathological changes seen with canine microsporidiosis.