Introduction
This is a condition characterised by a sudden increase in mortality in young, typically 7-14-day-old, rapidly growing broiler chickens. Birds in good condition die after showing neurological signs. Mortality drops off as sharply as it started. This appears to be a multifactorial condition. Feed intake, and/or carbohydrate absorption are disturbed resulting in a hypoglycaemia. Males are more susceptible than females, probably because they are growing faster. Filtered intestinal contents from affected flocks appear to be capable of reproducing the condition, suggesting a viral component. In order to reproduce the typical condition the affected birds are subject to 4 hours without feed and then a mild physical stress such as spraying with cool water.
Signs
- Tremor.
- Paralysis.
- Coma.
- Death.
- Orange mucoid droppings.
Post-mortem lesions
- Mild enteritis.
- Excess fluid in lower small intestine and caecae.
- Dehydration.
Diagnosis
Pattern of mortality.
Signs and lesions.
Treatment
Leave affected chicks undisturbed.
Provide multivitamins, electrolytes and glucose solution to flock.
Minimise stress.
Prevention
Good sanitation of the brooding house.
Avoidance of interruptions in feed supply.
Avoidance of physical stress.
Spirochaetosis
Introduction
The bacterium Borrelia anserina infects chickens, turkey, geese, ducks, pheasants, grouse and canaries with morbidity and mortality up to 100%. It is transmitted by arthropods, e.g. Argas persicus, and occasionally by infected faeces. The bacterium is poorly resistant outside host but may be carried by Argas persicus for 430 days. Brachyspira pilosicoli, previously known as Serpulina pilosicoli, is an intestinal spirochaete that can be associated with inflammation of the large intestine in a broad range of mammals and birds. It has been associated with typhilitis, diarrhoea, reduced egg production, and egg soiling in chickens.
Signs
- Depression.
- Cyanosis.
- Thirst.
- Often diarrhoea with excessive urates.
- Weakness and progressive paralysis.
- Drops in egg production may be seen in both systemic and intestinal forms
Post-mortem lesions
- Marked splenomegaly.
- Spleen mottled with ecchymotic haemorrhages.
- Liver enlarged with small haemorrhages.
- Necrotic foci.
- Mucoid enteritis.
Diagnosis
Haematology, isolate in chicken eggs or chicks or poults.
Treatment
Various antibiotics including penicillin.
Prevention
Control vectors, vaccines in some countries.