Egg Yolk Peritonitis in Chickens

What Is Egg Yolk Peritonitis? 

Egg yolk peritonitis (EYP) is a common and potentially serious condition in laying hens. It occurs when egg yolk material ends up inside the abdominal cavity instead of traveling normally through the reproductive tract. 

Egg yolk outside the oviduct acts like a foreign substance, triggering inflammation and often bacterial infection of the abdominal lining (peritonitis). Without treatment, the condition can progress and become life-threatening. 

Why Does Egg Yolk Peritonitis Happen? 

Several factors can contribute, including: 

• Internal laying 

The yolk fails to enter the oviduct and is released into the body cavity. 

• Egg rupture inside the body 

Fragile or malformed eggs may break before being laid. 

• Reproductive tract disease 

Infection, inflammation, tumors, or scarring of the oviduct can interfere with normal egg passage. 

• Hormonal or production stress 

Hens bred for high egg production are at increased risk. 

Signs You May Notice at Home 

Egg yolk peritonitis often develops gradually. Common signs include: 

• Abdominal swelling or bloating 
• Lethargy or sitting fluffed up 
• Decreased appetite or refusal to eat 
• Sudden drop or stop in egg production 
• Weight loss with a wide-based or “penguin-like” stance 
• Labored or rapid breathing due to abdominal pressure 

In some cases, fluid may be felt in the abdomen during gentle handling. 

How Is Egg Yolk Peritonitis Diagnosed? 

Your veterinarian may recommend one or more of the following: 

• Physical examination to assess abdominal fluid or discomfort 
• Ultrasound or X-rays to evaluate fluid buildup or egg material 
• Bloodwork to assess infection, inflammation, or organ stress 
• Abdominal fluid sampling to confirm yolk material and infection 

Treatment Options 

Treatment depends on how advanced the condition is and the hen’s overall health. Possible treatments include: 

• Supportive care 

Fluids, warmth, pain control, and nutritional support 

• Antibiotics and anti-inflammatory medications 

To control infection and reduce discomfort 

• Abdominal fluid drainage 

Can provide temporary relief from pressure but is not a cure 

• Hormonal therapy (such as a deslorelin implant) 

May reduce or stop egg production and decrease recurrence 

• Surgery (spay / salpingohysterectomy) 

A permanent solution, but often risky and not always feasible in backyard hens 

Your veterinarian will help determine which options are appropriate for your bird. 

Prognosis 

• Mild cases may respond to medical management, but recurrence is common ● Severe or repeated cases often carry a guarded to poor prognosis 
• The goal is often to improve comfort and quality of life rather than achieve a cure 

Can Egg Yolk Peritonitis Be Prevented? 

While not all cases can be prevented, risk may be reduced by: 

• Providing balanced nutrition with appropriate protein and calcium 
• Monitoring egg production and behavior for early changes 
• Avoiding breeding or selecting for extreme egg production 
• Seeking early veterinary care when abnormalities are noticed 

Heritage or lower-production breeds may have fewer reproductive complications than commercial layers. 

When to Call Your Veterinarian 

Contact a veterinarian experienced with poultry if your hen shows: 

• Sudden lethargy or loss of appetite 
• Abdominal swelling or bloating 
• Unexpected cessation of egg laying 
• Labored breathing or abnormal posture 

Take-Home Message 

Egg yolk peritonitis is common, serious, and often progressive, but early recognition and veterinary care can improve comfort and, in some cases, extend a hen’s quality of life. Thoughtful flock management and prompt attention to changes are key. 

If you have concerns about your hen or flock, our veterinary team is here to help.