In domestic fowl, cystic right oviduct is typically a necropsy finding that rarely affects commercial flock performance. However, reproductive problems are a common reason for evaluation of backyard hens by avian veterinarians.
Etiology of Cystic Right Oviduct in Poultry
As with most avian species, normal mature hens have only a left ovary and oviduct. The right Müllerian duct, which gives rise to the right side of the female reproductive tract, forms during embryonic development but normally regresses prior to hatching. Persistence of vestigial tissues from the right oviduct (or ovary) may result in formation of a cyst, a condition termed cystic right oviduct.
Epidemiology of Cystic Right Oviduct in Poultry
Cystic right oviduct is common in domestic fowl. An increased incidence has been observed in flocks after infectious bronchitis virus outbreaks (1).
Clinical Characteristics of Cystic Right Oviduct in Poultry
Clinical signs of cystic right oviduct may include an enlarged, fluctuant coelomic cavity as well as vague signs such as weakness, lethargy, decreased appetite, and decreased egg laying.
A cystic right oviduct manifests as an abdominal coelomic cystic structure filled with clear or whitish fluid and attached by a narrow stalk to the right side of the cloacal wall. Cysts may range in size from barely perceptible to 15–20 cm in diameter.
Diagnosis of Cystic Right Oviduct in Poultry
A cystic right oviduct may be palpable as a distended cystic structure, although small cysts may be difficult to detect. Given the lack of a diaphragm and the dorsal location of the lungs, birds with suspected coelomic fluid should not be positioned in dorsal recumbency.
Radiography or ultrasonography can confirm the presence of coelomic fluid or a discrete fluid-filled structure.
Coelomocentesis can allow sampling of fluid for cytologic evaluation or microbial culture and support a tentative diagnosis. Neoplasia, cystic hyperplasia of the left oviduct, and ascites should be considered as differential diagnoses.
Treatment of Cystic Right Oviduct in Poultry
Exploratory coelomic surgery may be attempted to remove the cystic right oviduct. Prognosis for resolution with treatment is fair to poor.
References
Mueller Slay A, Franca M, Jackwood M, Jordan B. Infection with IBV DMV/1639 at a young age leads to increased incidence of cystic oviduct formation associated with false layer syndrome. Viruses. 2022;14(5):852. doi:10.3390/v14050852
For More Information
Greenacre CB. Reproductive diseases of the backyard hen. J Exot Pet Med. 2015;24(2):164-171. doi:10.1053/j.jepm.2015.04.004
