Occurrence: Worldwide. Species affected: Chicken. Age affected: Young (1-6 weeks).

Causes: Unknown. Various viruses, eg. REO, Rota, corona, calici, Toga etc. may play a role, combined with nutritional and possibly genetic factors.

Effects: Incubation period is 7-14 days. Stunting, abnormal feathering, pale comb, wattles and legs are seen. Higher early mortality, weak legs, CNS signs.

There are a number of enteric disease conditions affecting young poultry that go undiagnosed with respect to identifying a definite aetiological agent. Thus a group of diseases of the nature have been termed "viral enteritis" but diseases with similar signs have been reported from many different countries under many different names. These include "malabsorption syndrome" "infectious stunting syndrome" broiler runting syndrome" "pale bird syndrome" and "helicopter disease".

Reported observations provide strong evidence that this is an infectious disease, although the involvement of non-infectious agents has not been completely ruled out. Because no recognised enteropathogen(s) has been consistently incriminated as the aetiological agent, research has discovered and/or identified numerous viral agents.

Several viruses have either been observed or isolated from the intestinal tract of chickens experiencing viral enteritis. A number of viral particles resembling either caliciviruses, coronaviruses, togaviruses, parvoviruses and picornalike viruses (pseudopicornaviruses) have been identified. One virus isolated from the intestines of four-day-old chickens showing signs of infectious stunting syndrome has been named the FEW virus. However, it should be remembered that the isolation of a particular viral agent does not in itself constitute a cause and effect relationship for the disease.

Incubation period of 7-14 days.

Stunting (stunting or runting syndrome), abnormal feathering (helicopter disease), pale comb, wattles and legs in broilers (pale bird syndrome) are seen.

Higher early mortality, weak legs, CNS signs (tremors, incoordination) and passage of undigested food in faeces can occur.

Enteritis can cause undigested feed in intestines and pale intestines, haemorrhages around heart may also be seen.

Anaemia seen as decreased pigmentation and atrophy of the pancreas and bursa of Fabricius can occur.

An enlarged proventriculus with glandular enlargement and a loss of the normal structural architecture (infectious proventriculitis) may be evident.

Brittle bones and femoral head necrosis with rickets, hydropericardium (water around the heart), a small flaccid (flabby) gizzard and encephalomalacia can often arise.

The clinical signs and gross lesions (particularly proventricular hyperplasia and atrophied pancreas) are characteristic.

A live vaccine at 1-2 days by injection and 6-8 weeks by injection, coarse spray or water and inactivated vaccine at 18-20 weeks for breeders will help control the disease.

It responds to antibiotics plus vitamin-mineral supplementation for control of secondary infection.

Vinegar in water (1%) kills viruses by reducing intestinal pH and reduces spread of virus and some clinical signs.

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