Predicting the Optimal Time of Breeding and the Possible Approaches for Treatment of Some Estrus Cycle Abnormalities in Bitches

Abstract

Infertility problem is a common syndrome among bitches and its causes are numerous, but the apparent most frequent cause is the mating at incorrect time. The aim of this study was to avoid the possible causes of infertility in bitches by predicting the optimal time of breeding and try to treat disorders in estrus cycles. A total number of 18 bitches of German shepherd breed were used in this study for monitoring phases of estrus cycle and predicting the optimal time of breeding. Those bitches examined by vaginal cytology, progesterone assay, measurement of vaginal PH, vaginal endoscopy and ultrasonographic examination of ovaries from proestrus to diestrus. By vaginal cytology, cornified cells first appeared on Day 4 from the beginning of proestrus, then increased till reached to 85% on Day 12 which is considered as the ovulation day. Measuring of progesterone concentration at the beginning of proestrus was very low (less than 1 ng/ml) then increased in 13 bitches only out of 18 bitches which used in this study till reach to 6.5 ± 1.37 ng/ml within ranges (4.8 to 8.3 ng/ml) on Day 12 from the beginning of proestrus. The other five bitches showed disorders in normal sequence of estrus cycle which was discovered by progesterone assay, vaginoscopy and ultrasonography of ovaries. Abnormalities in estrus cycle were recorded; two cases of anovulation and three bitches of persistent proestrus. As a trial for correcting the deviated estrus cycle, we injected hCG hormone in two anovulatory bitches for occurrence of ovulation, and also used methergine drug in cases of persistent proestrus as a trial for stoppage of continuous bloody discharge. The optimal time of breeding in 13 ovulatory bitches was within 2 to 3 days after ovulation day. Pregnancy rate after breeding by 20 days was recorded by ultrasonographic examination was 92.3 % (12/13 bitches). When applying these applications, we concluded that progesterone hormone assay was the accurate method for predicting the ovulation time and achieving higher pregnancy rate , and also can judge on estrus cycle if normal or abnormal.