Description
The genesis, evolving and spontaneous regression of a single luteinised ovarian cyst in a cyclic nulliparous Serrana goat, during the breeding season, were presented. Daily ovarian and uterus transrectal ultrasonography scanning was performed during two consecutive (induced and natural) oestrous cycles. Blood samples were collected every 4 h during the first 24 h after onset of each oestrus, detected by a vasectomised buck, in order to identify the timing of LH preovulatory peak. Plasma progesterone (P4) levels were also evaluated, twice a week, by RIA. After first induced oestrus (with 50 µg of cloprostenol, IM), sexual behaviour and mount acceptance were observed, but the preovulatory LH peak and ovulation were not detected. The luteinisation of a persistent follicle was observed by ultrasonography and the plasma P4 levels increased from 0.2 ng/ml to 2.5 ng/ml. The ovarian cyst reached 20 mm in diameter, 16 days after induced oestrus. On 19th day, a natural oestrus with a LH peak (109.2 ng/ml) and ovulation was observed. Corpora lutea was visualized in presence of cyst that decreased to 5 mm on 10th day of the second oestrous cycle, when P4 levels reached 9.0 ng/ml. A heterogeneous ultrasonographic appearance of uterine horns was observed in presence of the cyst, but not during the dioestrus of the second oestrous cycle. This case showed the occurrence and spontaneous recovery of a luteinised ovarian cyst associated with low (subnormal) plasma P4 levels and heterogenic texture of uterus in a young cyclic goat.
; Baril, Gérard 
