Cystic enteritis (runting syndrome)

Occurrence: Worldwide.
Species affected: Broilers
Age affected: 2-6 weeks
Causes: Unknown enteric viruses. Spread by vertical or horizontal routes and faecal contamination.
Effects: Incubation period is 7-14 days. Stunting, higher early mortality, and passage of undigested food in faeces can also occur. 



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 this nature have been termed “viral enteritis” but diseases with similar signs have been reported from many different countries under many different names.

Several viruses have either been observed or isolated from the intestinal tract of chickens experiencing this disease. Caliciviruses, reoviruses, coronaviruses, astroviruses, and parvoviruses have been identified so far. However, astroviruses have been most consistently isolated from birds with this disease. 

Clinical signs

Incubation period of 7-14 days. Stunted growth weight, higher early mortality, and passage of undigested food in faeces can occur.

Postmortem lesions

Enteritis which causes undigested feed in intestines and pale intestines. Microscopically there is  cystic in the intestinal villus of the Krypts.

Prevention & treatment

Total cleanup and disinfection of the house. An experimental vaccine against astroviruses has shown efficacy against one form of the disease. 

Cystic enteritis insights

Examining runting and stunting syndrome of broilers

USPOULTRY and the USPOULTRY Foundation have completed a funded research project at the University of Georgia on research that enhances the understanding of runting and stunting syndrome of broilers.