Hugo A. MEDINA
DVM, MS, DACPV,
Sparboe Companies, Litchfield, Minnesota, U.S.A.
Peritonitis in commercial layers causes significant negative economic consequences to the egg industry in the U.S.A.
There is no published information to date that document the total economic impact to the egg industry or the cost to the producer when flocks experience high mortality and/or the reduction in egg production due to this disease.
Peritonitis is a serious problem for the egg industry. It appears that this problem has been kept out of the research scope, and people who experience this problem only talk about it to close associates. People are reluctant to share their experiences with the challenge, so there is little information about the onset and process of the disease in the field and the successes or failures of treatments implemented to reduce mortality.
The only way we are going to understand the factors and/or causes that initiate the disease process of Peritonitis in commercial egg layers and to prevent the problem is by; reviewing published information, collecting anecdotal information, comparing treatments used, a epidemiology study and ultimately, initiating research projects that can test hypothesis and field experiences.
Abdominal Cavity
The peritoneum is a serous membrane lining the abdominal-pelvis (ceolomic) cavity walls and investing the viscera inside them. This strong colorless membrane with a smooth surface forms a double-layered sac. The potential space between the parietal and visceral peritoneum is called the peritoneal cavity.
The ceolomic cavity is the largest area of the body of the hen. This cavity contains among others the largest air sacs (abdominal sacs), most of the digestive tract organs (proventiculus, gizzard, and entire small intestine, part of the large intestine, liver and pancreas), genital-urinary systems (kidneys, ureters, ovary, most of the oviduct and atrophied right oviduct) and the spleen.
Some of the facts known about Peritonitis are:
- It is the most common cause of mortality in commercial layers and breeders.
- It also can affect other types of female birds, especially ducks and geese.
- Airsacculitis, Salpingitis and septicemia can be present in conjunction with the Peritonitis lesions.
- Peritonitis appears to be an acute problem.
- A flock does not appear to be sick or in distress.
- Peritonitis is common in layers, but not in pullets.
- In general, egg production is not affected, but is reduced due to mortality.
- Daily bird mortality appears normal a day prior to sudden mortality.
- Birds do not look sick. Affected birds are often in good physical condition, having full crops and in good egg production.
- Peritonitis is the inflammation of the peritoneum. The condition is marked by exudations in the peritoneum membranes and any of the organs within the abdominal cavity.
Characteristic Peritonitis lesions are an inflammatory response. Serous and edematous exudates tend to accumulate in the ceolomic cavity. Exudates undergo cessation to form a firm, dry, yellow, irregular, cheese-like mass. Time determines the extent and size of the exudates.
Peritonitis can be initiated in and affect other organs. Organs that can be affected are ovaries (oophoritis), oviduct (Salpingitis) air sac (airsacculitis), intestinal tract (enteritis) and systemic (septicemia) infection. The most common bacteria isolated from peritonitis lesions is Escherichia coli (E. coli) and in a lesser frequency other bacteria types, including Enterococcus, Pasteurella, Salmonella, Staphylococcus and Streptococcus.
E. coli, a Gram negative bacterium normally present in the intestinal tract of poultry and other animals, is the most common bacteria isolated in poultry worldwide. The most common pathogenic E. coli in poultry have been O1, O2, O35, and O78 serotypes. New serotypes have been linked to Colibacillosis in poultry.
Lesions by E. coli should not be referred to by the name E. coli alone, without the descriptor "coliform" being added, because other opportunistic bacteria can behave similar to E. coli in secondary infections.
The following table describes the known or suspected factors that increase host susceptibility to E. coli infections in poultry.
An additional factors not indicated in the table above, but might influence the development of peritonitis is high egg production, associated with estrogenic activity which may predispose to salpingitis (infection in the oviduct) by relaxing the sphincter between the vagina and cloaca.
Other factors that could play a role in the development of peritonitis are:
- incorrect beak treatment
- large egg size,
- low body weight,
- inadequate skeletal development
- high Ammonia levels
- airsacculitis
- enteric disturbances
- old cage equipment
- rough handling during bird transfers
- sub-lethal vent cannibalism
- sub-lethal partial prolapse
- high barn environmental temperatures
- fat accumulation in abdominal cavity
- high light intensity
E. coli is the most common bacteria isolated from mortality due to Colibacillosis with Peritonitis or other related lesions (airsacculitis, egg yolk peritonitis, internal layer, omphalitis, pericarditis, and perihepatitis). Infection occurs when E. coli ascends the oviduct from the cloaca causing Salpingitis and possible Peritonitis.
It appears that pathogenic E. coli can induce peritonitis lesions without the presence of predisposing factors. The layer industry has adopted the use of autogenous E. coli bacterins as a preventive for peritonitis control.
Prevention might be best accomplished by reducing and/or minimizing the presence of respiratory diseases through an adequate spectrum of vaccines like IBV and MG. At this point, we do not know the role of Mycoplasma synoviae in commercial layers.
In our experience, increase air movement and prevention of dusty conditions will help reduce respiratory diseases and peritonitis.
References
1. Y.M. Saif, 2003. Disease of Poultry, 11th Edition Iowa State University Press.
2. A.S. King and J. McLelland, 1984. Birds Their Structure and Function, Second Edition. Bailliere Tindall.
3. Kenton Kreager 2004. Emerging Diseases and Conditions in Layers Symposium. American Association of Avian Pathologists. Philadelphia 2004.
4. Bernie Beckman, 2004. Peritonitis, Layer School I University of Minnesota December 1, 2004.
5. Dorland's Illustrated 27th Edition Medical Dictionary 1985. W. B. Sanders Company.
From Proceedings of the "Midwest Poultry Federation Convention", St. Paul, Minnesota, U.S.A.
It is the most common cause of mortality in commercial layers and breeders.
