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Erysipelas in Layer Flock Noted in Monthly Report

by 5m Editor
29 May 2009, at 10:12am

UK - The Monthly Scanning Surveillance Report for April 2009 from the Veterinary Laboratories Agency (VLA) highlights acute erysipelas in a commercial layer flock with a history of increased mortality around peak lay. An Aspergillus fungus caused respiratory problems in a broiler flock, and duck virus hepatitis was diagnosed in backyard ducks and wild birds.

Commercial Layers

Parasitic enteritis

A problem of birds not coming into lay was investigated. Birds were transferred to the premises at 17 weeks of age but had not adequately come into lay. This was not highlighted until the birds were 37 weeks of age. Three birds were submitted and one had a heavy endoparasite infestation of Ascarid and Heterakis species and was in poor bodily condition. This bird had an inactive ovary. A further bird had an ulcerative proventriculitis and louse infestations were also detected. One of the other birds was in lay with a shelled egg in the lower oviduct and the third bird had only moderately sized sparse follicles on the ovary. No evidence of spirochaetal involvement was detected and management factors were thought to be possibly involved along with endoparasite infestation.

Erysipelas

Acute erysipelas was the diagnosis in a flock of 12,000, 50-week-old free-range layers with a history of significantly increased mortality from around 40 weeks. Egg production has remained good. Heavy pure growths of Erysipelothrix rhusiopathiae were obtained on culture of liver and spleen from septicaemic carcasses. A smaller flock of identical birds in another house on the farm have not been affected.

Broiler Chickens

Fungal pneumonia was diagnosed in a flock of 29-day-old broilers submitted with a history of stunting and abnormal vocalisation. Nodular lesions in the lower trachea/syrinx, lungs and thoracic air sacs were confirmed histopathologically as chronic fungal granulomas with septate branching fungal hyphae within the lesions. Fungal cultures produced good growths of Aspergillus versicolor. The bedding (sawdust) was said to be dry and in good condition.

Game Birds

Poor egg production was described in a breeding flock of approximately 170 pheasants. Post mortem examination of four birds showed a severe nephropathy associated with urate deposits over the pericardium and the liver (visceral gout). Histology of the kidney showed a severe nephritis varying from acute granulocytic tubulonephritis to a chronic granulomatous nephritis. Pheasant coronavirus infection was suspected.

Ducks and Geese

Three out of 20 backyard ducks died and the affected birds were either Muscovy or mixed breed ducks. An adult female Muscovy duck carcass was submitted for post mortem examination. Watery blood stained liquid was present in the cloaca and there was necrosis of the pharynx, oesophagus and cloaca. The liver was enlarged and reddened with multifocal pinpoint haemorrhages. Histological examination of the liver showed random foci of hepatic necrosis associated with intranuclear inclusions in hepatocyte and bile duct epithelium nuclei. The oesophagus showed an ulcerative oesophagitis with both intranuclear and intracytoplasmic inclusions. The findings were consistent with duck virus enteritis. The diagnosis of the infection in wildlife (see below) suggests this as a possible source of infection.

Wild Birds

The death of swan in a zoological collection lead to its submission to Winchester for post mortem examination. Findings were of a watery gut content with diphtheritic areas present on the mucosa of the proximal small intestine. Virus isolation confirmed the presence of Duck Virus Enteritis (DVE).

Shrewsbury diagnosed Duck Virus Enteritis in a Canada goose which had been found dead on a small lake. It had been in good bodily condition but with minimal food material in the intestinal tract. Histopathology suggested the possibility of viral infection and Duck Virus Enteritis herpes virus was subsequently isolated from tissues.

Further Reading

- You can view the full report by clicking here.

Further Reading

- Find out more information on the diseases mentioned in this article by clicking here.