Small Animal Abdominal and Metabolic Disorders Q&A 08

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A one-year-old, female German Shorthaired Pointer has had clinical signs of oestrus and male attractiveness for 45 days. The bitch is clinically well. Examination of a vaginal smear shows the presence of 75% anuclear cells and an absence of neutrophils. An ultrasound examination of the ovaries has been performed and an image obtained of the left ovary.

Question	Answer		Article
What is your diagnosis?	The ultrasound image shows an enlarged ovary with multiple anechoic structures of varying shape and size present throughout the stroma. This appearance is consistent with follicular cysts. Follicular cysts produce oestrogen and are usually associated with clinical signs of persistent oestrus. In some bitches the persistent elevation of oestrogen (hyperoestrogenism) can cause bone marrow suppression resulting in anaemia and thrombocytopenia. This ovary can be distinguished from a normal oestrus ovary because the latter generally has a smaller number of follicles of similar size. Follicles normally increase in size and ovulate when they reach approximately 11 mm in diameter.		[[|Link to Article]]
How common is this condition, and what are the differential diagnoses?	True follicular cysts are rare in the bitch. Cysts associated with the ovary are common, but these are usually present within the ovarian bursa and are not endocrinologically active and therefore produce no clinical signs. Differential diagnoses of oestrogen-producing follicular cysts are those bitches with a long proestrus and/or oestrus and bitches with split oestrus syndrome. The former may not ovulate until as late as 30 days after the onset of proestrus and the latter generally have an absence of oestrous signs before a return at some future time; in both cases the ovaries are ultrasonographically normal. Some ovarian tumours may produce oestrogen and produce clinical signs of persistent oestrus. These bitches are usually systemically unwell and have ascites.		[[|Link to Article]]
How might this condition be treated?	It may be possible to induce either ovulation or luteinization of follicular cysts by the administration of human chorionic gonadotrophin. If successful, the bitch enters metoestrus and has a normal interoestrous interval of approximately seven months. If this treatment is not successful, exogenous progestogens may be used to suppress the follicles and cause a resolution of the clinical signs. In some cases, oestrus and ovulation follow shortly after progestogen withdrawal, whilst in others the interoestrous interval is delayed for up to four months.		[[|Link to Article]]
What is the likely chance of recurrence, and the significance for fertility?	After successful therapy or, occasionally, spontaneous regression, bitches frequently return to normal cyclicity with no reduction in fertility.		[[|Link to Article]]