CASE NOTES
Egg-Associated Peritonitis in a Small Backyard Hen Flock
Bruce Watt, Central Tablelands Local Land Services, Bathurst
Posted Flock & Herd March 2023
Introduction
Egg-associated peritonitis is a common cause of mortality in laying hens (Reece 2018). However, backyard poultry surveillance is warranted because the important diseases Avian Influenza, Newcastle disease and psittacosis need to be ruled out in cases of mortality.
History
The owner of a small flock of backyard hens in Bathurst reported that one hen had died several days previous and another was sick. Four Isa Browns had been obtained from a commercial poultry operation several months previous. The other four hens in the flock were heritage breeds. Only the Isa Browns were affected. The flock was fed on poultry mash and household scraps. The feed bins were wired off to prevent wild bird access.
Clinical findings
One mature Isa Brown was examined on 29 July 2022. The hen had reasonable muscle cover over the sternum and pasty faeces on the cloaca. It sat in sternal recumbency and was unable to raise its head although it could right itself if placed on its side. The legs and wings were drooping but had some muscle tone and while there was no menace response the bird's eyes constricted with light.
Necropsy findings
The bird was euthanased and necropsied. A small free egg was found in the peritoneal cavity and there was scant turbid yellow peritoneal exudate. While egg-associated peritonitis was diagnosed grossly, samples were submitted to exclude notifiable diseases.
Laboratory Findings
Samples were negative for Influenza A virus, Newcastle Disease virus and Chlamydia psittaci.
Figure 1. The affected bird was weak and unable to raise its head
Figure 2. A small free egg in the peritoneal cavity.
Reference
- Reece R. Backyard and Fancy Poultry. Management, Health, Treatment and Diseases. Posted on Flock and Herd August 2018 www.flockandherd.net.au