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Unusual Leg Problems Diagnosed in Pullet Flocks

by 5m Editor
24 March 2009, at 8:05am

UK - The Monthly Surveillance Report from the Veterinary Laboratories Agency (VLA) for January 2009 highlights spiking mortality and starvation as the cause of high mortalities in two commercial flocks. Lameness in young broiler breeders was attributed to traumatic tendon ruptures, and rickets was diagnosed in layer pullets with leg problems.

Broiler Chickens

Colisepticaemia

E. coli septicaemia in combination with yolk sac infection or septic arthritis was diagnosed in four batches of chicks aged between 3 and 4 days with increased mortality over the past two days.

Spiking mortality syndrome

Spiking mortality syndrome (probable hypoglycaemia) was thought to be the main cause of sharp and transient increase in mortality in a flock of 28-day-old broilers. Post-mortem examination findings included congested subcutaneous fat and livers, pale spleens with blood splashes and absence of food in the upper digestive tract. Although a definitive diagnosis for this condition depends on the demonstration of blood glucose levels below 150 mg/dl, a microscopic finding of numerous lipid droplets in renal tubular epithelium and myocardial cells which are demonstrated by Oil Red 'O', supports the possibility of a metabolic problem, e.g. hypoglycaemia, resulting in the mobilisation of fat stores as an alternative energy source.

Broiler Breeders

Traumatic tendon ruptures

Traumatic tendon ruptures were diagnosed in a flock of 27-week-old birds submitted with a history of increase lameness. The main finding at post mortem examination was of recent often unilateral gastrocnemius tendon rupture just above hock level accompanied by bruising and tissue discoloration.

Commercial Layers

Starve out and dehydration

High mortality in a flock of 7-day-old chicks showing little or no sign of growth was associated with starve out and dehydration. Post mortem examination revealed virtually empty gastro-intestinal tracts with only small amounts of litter present in the gizzard. The kidneys were pale with small amount of urates present in the ureters.

Rickets

Rickets was diagnosed in two flocks aged 18 and 25 days. All had a history of recent onset of lameness and were below target weight and uneven. There was no increased mortality. Findings at post mortem examination were of poor bone strength affecting leg bones in particular, and slight enlargement of parathyroid glands in one of the cases. Histological examination of undecalcified sections of growth plates stained by von Kossa's method confirmed osteodystrophic changes and patchy mineralization failure consistent with rickets.

Erysipelas

Acute septicaemia due to Erysipelothrix rhusiopathiae was confirmed in two flocks of free-range layers aged 65 and 76 weeks in which a slightly raised mortality rate had been in evidence over the past few weeks.

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.