Estrus, Prolonged

Estrus, Prolonged



Basic Information image



Definition


Estrous behavior lasting more than 12 days



Synonym(s)


Persistent estrus, nymphomania



Epidemiology



Species, Age, Sex


Sexually mature mares



Risk Factors


Endometritis



Geography and Seasonality




• Prolonged estrus during spring transition between January and April (Northern Hemisphere)


• Hemorrhagic anovulatory follicles are more common during the fall



Associated Conditions and Disorders




• Endometritis


• Ovarian disorders



Clinical Presentation



History, Chief Complaint


Signs of estrus for >12 days (normal duration 5–7 days with a range of 2–12 days)



Physical Exam Findings


Body condition generally good



Etiology and Pathophysiology




• Seasonality: Prolonged estrous behavior during spring transition or winter anestrus


• Granulosa theca cell tumor (GTCT): Increased production of estrogens or lack of progesterone


• Gonadal dysgenesis: 63,XO; 65,XXX; 64,XY mares


• Hormone imbalance: Older mares may fail to ovulate and exhibit prolonged estrus; possibly due to insufficient or ineffective leutinizing hormone release


• Previous ovariectomy


• Hemorrhagic anovulatory follicles (HAF): 14.3% remain as follicular structures with consequent signs of persistent estrus



Diagnosis image



Differential Diagnosis




• Frequent urination


image Cystitis/urethritis

image Bladder atony

• Frequent posturing and straining


image Urovagina

image Vaginitis

image Pneumovagina

• Submissive behavior


• Missed shortened interestrus


• Psychogenic behavioral problem not associated with physiologic or pathologic causes of prolonged estrus



Initial Database




• Teasing: Estrous behavior


• Transrectal palpation and ultrasound: Serial examinations may be needed to evaluate the estrous cycle and its association with behavior.


image Anestrus: Small inactive ovaries, no uterine edema, relaxed cervix.
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Jul 24, 2016 | Posted by in SMALL ANIMAL | Comments Off on Estrus, Prolonged

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