A bacterial proventriculitis in canaries (Serinus canaria).

A description is given of the pathomorphology and pathomorphogenesis of a bacterial infection of the proventriculus of canaries. The cause appeared to be a large, rod-shaped, Grampositive bacterium, in which no spore formation could be observed. Cultivation in vitro has not as yet been achieved. Thirty % of the 30 canaries examined contained this bacterium in the proventriculus. In the rest of the digestive tract much smaller numbers were found. The bacteria were associated with a proliferative inflammatory reaction in the proventriculus. The infected proventriculi had an increased pH and an altered synthesis of mucopolysaccharides. The coilin layer of the gizzard was thinner in the infected canaries than in the control group, possibly as a result of the increased pH in the proventriculus.