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Oestrous Cycle - Anatomy & Physiology (view source)
Revision as of 14:21, 11 September 2008
, 14:21, 11 September 2008no edit summary
=== Endocrine Changes during the Oestrous Cycle ===
=== Endocrine Changes during the Oestrous Cycle ===
* The luteal phase is prolonged compared to other species, this is shown by persisting levels of progesterone in the bloodstream.
* Progesterone levels begin to rise 60-70 hours before ovulation has occured. This is evidence of pre-ovulatory luteinisation of mature follicles.
* The pre-ovulatory rise in progesterone may signal the bitch to accept the male.
* Oestrogens rise rapidly before the onset of standing oestrus.
* The LH surge rapidly follows and lasts longer than in other species.
* Ovulation occurs 24-96 hours after the LH surge.
* FSH levels peak at the same time as the LH surge.
* As progesterone levels fall towards the end of metoestrus or pregnancy, prolactin increases.
* Prolactin is a major luteotrophic hormone in the bitch.
=== Pseudopregnancy ===
=== Pseudopregnancy ===