A SYNDROME-ASSOCIATED WITH GROWTH DEPRESSION AND AMYLOID ARTHROPATHY IN LAYERS - A PRELIMINARY-REPORT

In heavy breed layers a new syndrome was encountered, associated with impaired growth. The disease developed from 5 to 6 weeks onwards. Morb idity in most flocks was 1 to 4%, but in some cases up to 20%. The aff ected birds were smaller in size, made a peeping sound like that of yo unger chickens, and showed a characteristic stiff gait. The stifle and hock joints were swollen. At necropsy 12 out of 66 affected birds (18 %) had bronze-coloured livers and 23 out of 66 (35%) had orange-colour ed joint deposits. Histology indicated that these birds appeared to ha ve amyloidosis. The amyloid was found to react positively with anti-du ck and anti-bovine amyloid protein A antisera on PAP-staining, indicat ing it to be of the reactive type. The cause of the syndrome is unknow n. A possible association with infectious agents (Streptococcus faecal is and reovirus) is discussed.