Free-Range Flocks Also Suffer Cannibalism

UK - The Monthly Scanning Surveillance Report for July 2009 from the Veterinary Laboratories Agency (VLA) highlights severe cannibalism in two free-range layer flocks and infectious laryngotracheitis as the cause of sudden death in broiler breeders.
calendar icon 11 September 2009
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Commercial Layers and Layer Breeders

Vent pecking

Cannibalism and vent pecking were seen in two free-range flocks of 28 and 64 weeks of age. Findings at post-mortem examination were of chronic vent pecking damage associated with E. coli egg peritonitis and pale carcasses, in which often the entire length of the intestinal and oviduct tract were missing.

Red mite

A commercial unit hatching rare breed chicks every 10 days for the 'hobby sector' was experiencing increasing mortality up to 10 days of age. Somewhat unusually in such a small flock, a heavy red mite infestation (Dermanyssus gallinae) was evident. Birds were noticeably anaemic in appearance, and most birds had not fed. Relevant advice on ectoparasite control was given.

Broilers and Broiler Breeders

Gizzard impaction

Impaction of gizzard and upper intestine was seen in three batches of free- range broilers aged 26, 43 and 56 respectively all from the same farm. The history was of poor performance and unevenness. Post-mortem examination revealed a marked distension of the gizzard and duodenum with large bundles of long plant fibres (probably a mixture of the straw bedding and grass), with virtually no grit present. A review of grit provision and bedding/ pasture management was indicated.

Infectious laryngotracheitis

Infectious laryngotracheitis (ILT) was diagnosed in a house of 57-week-old birds with a sudden increased in mortality. Birds were seen with watery eyes and mild dyspnoea. Lesions at post-mortem examination included plugs of necrotic caseous debris occluding the larynx. Histological examination confirmed a severe tracheitis with numerous syncytia containing intranuclear inclusion bodies consistent with ILT.



Two thousand six- to eight-week-old pheasant poults had been bought in and housed in release pens. During the first night following arrival 60 birds died, the next night 50 were found dead and the following night a further 50. Six dead birds were presented to Sutton Bonington for necropsy which revealed two birds to have fractures to the distal humerus without associated haemorrhage and another bird significant haemorrhage along the body wall. Most of the birds had empty crops.

The finding suggested that that the poor weather following release had caused the birds to huddle together resulting in suffocation and trauma.


Carcasses of 11 partridge and pheasant poults were submitted to Langford following a history of poor body condition and loose droppings. The problem appeared to be more severe in younger birds but all groups had shown losses of up to 10 per cent from a flock with a total of 20,000 pheasant poults and 2,000 partridge poults. Post-mortem examination revealed evidence of Spironucelosis (hexamita infection).

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.
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