Salpingitis / Salpingoperitonitis

Etiology 

Avian pathogenic Escherichia coli (gram-negative, non-spore-forming bacillus).  Somatic (O) and capsular (K) antigens are often used to designate serotypes.  Serotypes with the somatic antigens 1, 2, 35, 78 are frequently associated with disease in poultry.  Most of the strains are motile.  Commonly, the strains isolated from flock with salpingoperitonitis poses type 1 fimbriae which allow them to attach to the oviductal epithelium. Listeria monocytogenes and Gallibacterium salpingitidis have occasionally been confirmed to be the etiological agent of salpingitis in ducks and geese.

Susceptibility of the agent

E. coli is inactivated at 60°C (140°F) for 30 min.  The organism is susceptible to desiccation.  Washing and drying surfaces completely eliminates the bacteria.  However, E. coli can also be inactivated in wet litter by heat treatment, especially in the presence of free ammonia.  Bacterial reproduction is inhibited at pH < 4.5.  Chlorine can be used to treat water.  E. coli can acquire resistance to disinfectants when subjected to environmental pressure.  The mechanisms for resistance are encoded in plasmids that can be shared between bacteria.

Occurrence

It is one of the most common causes of mortality in mature laying hens.  It is of notable importance in backyard flocks and pet birds since those animals can be kept for many years.  The prevalence of salpingoperitonitis is higher in older females.

Pathogenesis

E. coli can be isolated from the cloaca of normal animals.  Salpingitis occurs when E. coli migrates from the cloaca to the oviduct.  Estrogenic activity related to egg production relaxes the sphincter between the cloaca and vagina which facilitates the migration of ascending microorganisms into the oviduct.  Masses of exudate form in the oviduct.  Bacteria can compromise the oviduct wall and the most virulent strains can translocate into the abdominal cavity, leading to peritonitis.  Bacteria can also reach the peritoneum through the open end of the infundibulum.  Abdominal laying is possible and contribute to the severity of the peritonitis.  Mucosal infections with mycoplasma or viruses (like the infectious bronchitis virus) will predispose the animals to salpingoperitonitis.  Contamination of the oviduct can also derive from airsacculitis though this is more frequent in younger animals.  The immune system of the birds react with a rather mild inflammatory reaction (consisting mainly of heterophils and some lymphocytic foci in chronic cases) that seems unproportionate to the amount of accumulated exudate.

Clinical manifestations

Hens stop laying eggs (but do not necessarily stop ovulating).  In chronic cases, the masses of caseous exudate in the abdomen and oviduct cause abdominal distension, which feels hard upon palpation.  In chronic cases and due to the enormous amount of material accumulated in the oviduct, the animals will have difficulty walking and may walk adopting a "penguin-like" posture (picture 1).

Picture 1. Penguin-like posture in a female chicken. Picture credit. Dr. E. Pendleton

Necropsy findings

Inflammation in the oviduct and peritoneal cavity.  In acute cases, a fluid exudate is present.  In chronic cases, the oviduct is distended with masses of solid exudate accumulating in its lumen (picture 2), often surrounding an egg.  The exudate, which can have massive proportions, has a laminated appearance due to repeated ovulation and secretion of albumen.  Abdominal laying is possible.

 
Picture 2. A large mass of caseous exudate in the oviduct. Picture credit Dr. E. Pendleton

Diagnosis

• Necropsy and detection of masses of exudate in oviduct and peritoneum 

• Culture of the organism

Prevention

None

Treatment

Antibiotics are not effective after caseous exudate builds up in the oviduct.  Surgery is followed by antimicrobial therapy in pet birds.

References 

Diseases of Poultry, 13^th ed. D. E. Swayne.  Wiley-Blackwell.

Avian Diseases Manual.  7^th ed. The American Association of Avian Pathologists.