- Ovaries are removed from mares for two reasons - pathologic changes or management practices.
- A number of different approaches and techniques are available to the surgeon.
- Ovariectomy is associated with a higher frequency of peri-operative complications than other elective surgical procedures.
- Removal of ovaries bilaterally from mares not intended for breeding, ie management reasons .
- Removal of ovarian neoplasia , eg teratoma , adenoma, adenocarcinoma granulosa cell tumor , lymphosarcoma .
- Treatment of choice for removal of ovarian neoplasia.
- Standing sedation can be used for ovariectomy via colpotomy.
- High frequency of peri-operative complications - some of which can be life-threatening.
- Technically difficult to exteriorise ovary and ligate it.
- Standard surgical kit.
- Associated with high incidence of peri-operative complications:
- Depends upon primary reason for surgery.
- Guarded for behavioral reasons - although normal oestrus cycles are prevented, this may not alleviate the abnormal behavior.
- Guarded for ovarian granulosa theca cell tumors .
- Unilateral resection: mares return to estrus in mean of 8.5 months (usually must go through the winter cycle).
- Once the normal cycle has started, fertility appears to be unaffected.
Reasons for treatment failure
- Failure to remove all ovarian tissue.