Question of the Day

A persistent corpus luteum (CL) on a mare’s ovary leads to anestrus during the breeding season. Remember, after ovulation of the dominant follicle a corpus hemorrhagicum (CH, or “bloody body”) forms on the ovary, which then matures in the CL in four to five days. 

The CL produces progesterone, which maintains pregnancy or diestrus. During a normal estrus cycle (mares are seasonally polyestrous), if the mare is not pregnant, luteolysis occurs in 14 days and the cycle continues. 

Persistent CL can be associated with uterine causes (e.g., early embryonic loss, pyometra) or be idiopathic. 

Tx with prostaglandin F2-alpha (10-15 mg) if the CL is mature, and the mare should come back into estrus in two to five days. Identify and treat any underlying causes as indicated.

Follicular cystic ovary disease is primarily a disease of dairy cattle.