Cystic Ovaries

This disease primarily affects breeding age sows. The key clinical signs include: sow continually on heat; pigs show discomfort; repeat matings.
calendar icon 13 November 2018
clock icon 7 minute read

Background and history

This is a common condition, particularly in old sows. Large cysts develop in the ovaries which often produce high levels of oestrogen.

The carcass is safe for human consumption.

Clinical signs

  • Abnormal heat.
  • Not accept the boar at mating.
  • Continually on heat.
  • Infertility.
  • Repeat matings.
  • Pigs show pain/discomfort.
  • May grind teeth.


Made on clinical grounds and normally only involves individual animals. Carry out a post-mortem examination of the ovaries.

Post-mortem lesions

  • Abnormally sized ovaries – 25mm in diameter.
  • Cysts 2–3cm in diameter in the ovaries, filled with clear fluid.
  • Occasionally regressing corpora lutea in ovary.


  • Age.
  • Hereditary.
  • Stress.
  • Mycotoxins.
  • Breeding.
  • Hormonal malfunctions.
  • Hormone misuse.
  • Mouldy bedding or food.
  • Badly stored grains.


  • Reduce causes of stress on sows.
  • Consider delayed weaning.


  • Culling of affected sows is most common.
  • Synthetic hormone treatment:
    • Progestogen by mouth
    • Gonadotrophic hormones by injection.

Emily Houghton

Editor, The Pig Site

Emily Houghton is a Zoology graduate from Cardiff University and was the editor of The Pig Site from October 2017 to May 2020. Emily has worked in livestock husbandry, and has written, conducted and assisted with research projects regarding the synthesis of welfare and productivity of free-range food species.

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