Oviduct impaction is a serious, life-threatening condition that affects hens actively laying eggs. Modern laying breeds are highly susceptible due to excessive egg laying. It occurs from the accumulation of eggs or egg material in the oviduct and is often a consequence of chronic
salpingitis.
E. coli is commonly associated with reproductive infections that lead to oviduct impaction in laying hens. Other bacteria found in conjunction include
Proteous spp,
Klebsiella spp and
Streptococcus spp. Oviduct impactions can less frequently be caused by excessive production of albumin or mucin or hens with cystic hyperplasia.
As the impacted mass grows in size it can fill up most of the chicken's body cavity, causing marked distension of the abdomen. The contains of the impaction may include inspissated albumin and yolk materials adhered to the mucosal surface, partially formed eggs and thin shelled eggs in the abdominal cavity. Oviduct prolapse or torsion of the oviduct may occur secondary due to the buildup of egg material and prolonged contractions.
Clinical signs that a hen may have an oviduct impaction include:
- Sudden cessation of egg laying for weeks to months
- Enlarged abdomen
- Weight loss
- Depression, change in behavior
- Reduced appetite
- Excessive nestbox sitting, often confused with acting 'broody'
Hens with oviduct impactions require surgery to remove the contents causing the obstruction (salpingotomy). Severe or chronic cases may require the complete removal of the oviduct (salpingohysterectomy). Hormone implants are a less risky alternative to stop hens from continuing to lay eggs.
